129479021 has 24 divisors (see below), whose sum is σ = 163827576. Its totient is φ = 101606400.

The previous prime is 129478991. The next prime is 129479057. The reversal of 129479021 is 120974921.

It can be written as a sum of positive squares in 4 ways, for example, as 29278921 + 100200100 = 5411^2 + 10010^2 .

It is not a de Polignac number, because 129479021 - 2⁶ = 129478957 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129479521) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 28721 + ... + 32921.

It is an arithmetic number, because the mean of its divisors is an integer number (6826149).

Almost surely, 2^129479021 is an apocalyptic number.

It is an amenable number.

129479021 is a deficient number, since it is larger than the sum of its proper divisors (34348555).

129479021 is a wasteful number, since it uses less digits than its factorization.

129479021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4269 (or 4262 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 35.

The square root of 129479021 is about 11378.8848750657. The cubic root of 129479021 is about 505.9020846642.

The spelling of 129479021 in words is "one hundred twenty-nine million, four hundred seventy-nine thousand, twenty-one".