129724057 has 4 divisors (see below), whose sum is σ = 133908736. Its totient is φ = 125539380.

The previous prime is 129724051. The next prime is 129724069. The reversal of 129724057 is 750427921.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-129724057 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (129724051) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2092293 + ... + 2092354.

It is an arithmetic number, because the mean of its divisors is an integer number (33477184).

Almost surely, 2^129724057 is an apocalyptic number.

It is an amenable number.

129724057 is a deficient number, since it is larger than the sum of its proper divisors (4184679).

129724057 is an equidigital number, since it uses as much as digits as its factorization.

129724057 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4184678.

The product of its (nonzero) digits is 35280, while the sum is 37.

The square root of 129724057 is about 11389.6469216565. The cubic root of 129724057 is about 506.2210194862.

The spelling of 129724057 in words is "one hundred twenty-nine million, seven hundred twenty-four thousand, fifty-seven".