15728729 has 2 divisors, whose sum is σ = 15728730. Its totient is φ = 15728728.

The previous prime is 15728717. The next prime is 15728747. The reversal of 15728729 is 92782751.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14077504 + 1651225 = 3752^2 + 1285^2 .

It is a cyclic number.

It is not a de Polignac number, because 15728729 - 2⁸ = 15728473 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (15728329) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7864364 + 7864365.

It is an arithmetic number, because the mean of its divisors is an integer number (7864365).

Almost surely, 2^15728729 is an apocalyptic number.

It is an amenable number.

15728729 is a deficient number, since it is larger than the sum of its proper divisors (1).

15728729 is an equidigital number, since it uses as much as digits as its factorization.

15728729 is an evil number, because the sum of its binary digits is even.

The product of its digits is 70560, while the sum is 41.

The square root of 15728729 is about 3965.9461670577. The cubic root of 15728729 is about 250.5520016132.

It can be divided in two parts, 1572 and 8729, that added together give a palindrome (10301).

The spelling of 15728729 in words is "fifteen million, seven hundred twenty-eight thousand, seven hundred twenty-nine".