15997218 has 16 divisors (see below), whose sum is σ = 32101056. Its totient is φ = 5314640.

The previous prime is 15997207. The next prime is 15997229. The reversal of 15997218 is 81279951.

It is an interprime number because it is at equal distance from previous prime (15997207) and next prime (15997229).

It is a self number, because there is not a number n which added to its sum of digits gives 15997218.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2421 + ... + 6152.

It is an arithmetic number, because the mean of its divisors is an integer number (2006316).

Almost surely, 2^15997218 is an apocalyptic number.

15997218 is an abundant number, since it is smaller than the sum of its proper divisors (16103838).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

15997218 is a wasteful number, since it uses less digits than its factorization.

15997218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8889.

The product of its digits is 45360, while the sum is 42.

The square root of 15997218 is about 3999.6522348824. The cubic root of 15997218 is about 251.9696045476.

The spelling of 15997218 in words is "fifteen million, nine hundred ninety-seven thousand, two hundred eighteen".