39128729 has 2 divisors, whose sum is σ = 39128730. Its totient is φ = 39128728.

The previous prime is 39128701. The next prime is 39128759. The reversal of 39128729 is 92782193.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 36481600 + 2647129 = 6040^2 + 1627^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-39128729 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (39128759) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19564364 + 19564365.

It is an arithmetic number, because the mean of its divisors is an integer number (19564365).

Almost surely, 2^39128729 is an apocalyptic number.

It is an amenable number.

39128729 is a deficient number, since it is larger than the sum of its proper divisors (1).

39128729 is an equidigital number, since it uses as much as digits as its factorization.

39128729 is an evil number, because the sum of its binary digits is even.

The product of its digits is 54432, while the sum is 41.

The square root of 39128729 is about 6255.2960761262. The cubic root of 39128729 is about 339.4938518454.

The spelling of 39128729 in words is "thirty-nine million, one hundred twenty-eight thousand, seven hundred twenty-nine".