129321620 has 12 divisors (see below), whose sum is σ = 271575444. Its totient is φ = 51728640.

The previous prime is 129321611. The next prime is 129321631. The reversal of 129321620 is 26123921.

It can be written as a sum of positive squares in 2 ways, for example, as 51811204 + 77510416 = 7198^2 + 8804^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 129321620.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3233021 + ... + 3233060.

It is an arithmetic number, because the mean of its divisors is an integer number (22631287).

Almost surely, 2^129321620 is an apocalyptic number.

129321620 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

129321620 is an abundant number, since it is smaller than the sum of its proper divisors (142253824).

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

129321620 is a wasteful number, since it uses less digits than its factorization.

129321620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6466090 (or 6466088 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 129321620 is about 11371.9664086736. The cubic root of 129321620 is about 505.6970018063.

The spelling of 129321620 in words is "one hundred twenty-nine million, three hundred twenty-one thousand, six hundred twenty".