129620 has 12 divisors (see below), whose sum is σ = 272244. Its totient is φ = 51840.

The previous prime is 129607. The next prime is 129629. The reversal of 129620 is 26921.

129620 = T₁₇₆ + T₁₇₇ + ... + T₁₈₃.

It can be written as a sum of positive squares in 2 ways, for example, as 91204 + 38416 = 302^2 + 196^2 .

It is a super-3 number, since 3×129620³ = 6533370783384000, which contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20), and also a Moran number because the ratio is a prime number: 6481 = 129620 / (1 + 2 + 9 + 6 + 2 + 0).

It is a junction number, because it is equal to n+sod(n) for n = 129592 and 129601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129629) by changing a digit.

129620 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3221 + ... + 3260.

It is an arithmetic number, because the mean of its divisors is an integer number (22687).

2¹²⁹⁶²⁰ is an apocalyptic number.

129620 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

129620 is an abundant number, since it is smaller than the sum of its proper divisors (142624).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

129620 is a wasteful number, since it uses less digits than its factorization.

129620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6490 (or 6488 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 129620 is about 360.0277767062. The cubic root of 129620 is about 50.6085629714.

Subtracting from 129620 its sum of digits (20), we obtain a square (129600 = 360²).

It can be divided in two parts, 12 and 9620, that multiplied together give a triangular number (115440 = T₄₈₀).

The spelling of 129620 in words is "one hundred twenty-nine thousand, six hundred twenty".