15997700 has 18 divisors (see below), whose sum is σ = 34715226. Its totient is φ = 6399040.

The previous prime is 15997691. The next prime is 15997703. The reversal of 15997700 is 779951.

It can be written as a sum of positive squares in 3 ways, for example, as 141376 + 15856324 = 376^2 + 3982^2 .

It is not an unprimeable number, because it can be changed into a prime (15997703) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 79889 + ... + 80088.

Almost surely, 2^15997700 is an apocalyptic number.

15997700 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

15997700 is an abundant number, since it is smaller than the sum of its proper divisors (18717526).

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

15997700 is a wasteful number, since it uses less digits than its factorization.

15997700 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 159991 (or 159984 counting only the distinct ones).

The product of its (nonzero) digits is 19845, while the sum is 38.

The square root of 15997700 is about 3999.7124896672. The cubic root of 15997700 is about 251.9721351570.

The spelling of 15997700 in words is "fifteen million, nine hundred ninety-seven thousand, seven hundred".