129951828 has 18 divisors (see below), whose sum is σ = 328489434. Its totient is φ = 43317264.

The previous prime is 129951823. The next prime is 129951839. The reversal of 129951828 is 828159921.

129951828 is a `hidden beast` number, since 129 + 9 + 518 + 2 + 8 = 666.

It can be written as a sum of positive squares in only one way, i.e., 124277904 + 5673924 = 11148^2 + 2382^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129951823) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1804851 + ... + 1804922.

It is an arithmetic number, because the mean of its divisors is an integer number (18249413).

Almost surely, 2^129951828 is an apocalyptic number.

129951828 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

129951828 is an abundant number, since it is smaller than the sum of its proper divisors (198537606).

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

129951828 is a wasteful number, since it uses less digits than its factorization.

129951828 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3609783 (or 3609778 counting only the distinct ones).

The product of its digits is 103680, while the sum is 45.

The square root of 129951828 is about 11399.6415733127. The cubic root of 129951828 is about 506.5171224941.

The spelling of 129951828 in words is "one hundred twenty-nine million, nine hundred fifty-one thousand, eight hundred twenty-eight".