15915685897 has 2 divisors, whose sum is σ = 15915685898. Its totient is φ = 15915685896.

The previous prime is 15915685883. The next prime is 15915685931. The reversal of 15915685897 is 79858651951.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8796376521 + 7119309376 = 93789^2 + 84376^2 .

It is a cyclic number.

It is not a de Polignac number, because 15915685897 - 2⁷ = 15915685769 is a prime.

It is not a weakly prime, because it can be changed into another prime (15915685817) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7957842948 + 7957842949.

It is an arithmetic number, because the mean of its divisors is an integer number (7957842949).

Almost surely, 2^15915685897 is an apocalyptic number.

It is an amenable number.

15915685897 is a deficient number, since it is larger than the sum of its proper divisors (1).

15915685897 is an equidigital number, since it uses as much as digits as its factorization.

15915685897 is an evil number, because the sum of its binary digits is even.

The product of its digits is 27216000, while the sum is 64.

The spelling of 15915685897 in words is "fifteen billion, nine hundred fifteen million, six hundred eighty-five thousand, eight hundred ninety-seven".