129621023 has 12 divisors (see below), whose sum is σ = 151718040. Its totient is φ = 110415312.

The previous prime is 129621001. The next prime is 129621047. The reversal of 129621023 is 320126921.

It is not a de Polignac number, because 129621023 - 2¹⁰ = 129619999 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 129620983 and 129621001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129621083) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 128 + ... + 16101.

It is an arithmetic number, because the mean of its divisors is an integer number (12643170).

Almost surely, 2^129621023 is an apocalyptic number.

129621023 is a deficient number, since it is larger than the sum of its proper divisors (22097017).

129621023 is a wasteful number, since it uses less digits than its factorization.

129621023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16406 (or 16399 counting only the distinct ones).

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

The square root of 129621023 is about 11385.1228803206. The cubic root of 129621023 is about 506.0869611043.

Adding to 129621023 its reverse (320126921), we get a palindrome (449747944).

The spelling of 129621023 in words is "one hundred twenty-nine million, six hundred twenty-one thousand, twenty-three".