129961320 has 64 divisors (see below), whose sum is σ = 394848000. Its totient is φ = 34215168.

The previous prime is 129961319. The next prime is 129961327. The reversal of 129961320 is 23169921.

It is a super-2 number, since 2×129961320² = 33779889392284800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (129961327) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2626 + ... + 16334.

It is an arithmetic number, because the mean of its divisors is an integer number (6169500).

Almost surely, 2^129961320 is an apocalyptic number.

129961320 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 129961320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (197424000).

129961320 is an abundant number, since it is smaller than the sum of its proper divisors (264886680).

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

129961320 is a wasteful number, since it uses less digits than its factorization.

129961320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13802 (or 13798 counting only the distinct ones).

The product of its (nonzero) digits is 5832, while the sum is 33.

The square root of 129961320 is about 11400.0578945898. The cubic root of 129961320 is about 506.5294546112.

The spelling of 129961320 in words is "one hundred twenty-nine million, nine hundred sixty-one thousand, three hundred twenty".