15998864 has 40 divisors (see below), whose sum is σ = 35646528. Its totient is φ = 6814080.

The previous prime is 15998861. The next prime is 15998909. The reversal of 15998864 is 46889951.

It is a happy number.

15998864 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (15998861) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23294 + ... + 23970.

Almost surely, 2^15998864 is an apocalyptic number.

15998864 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 15998864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17823264).

15998864 is an abundant number, since it is smaller than the sum of its proper divisors (19647664).

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

15998864 is a wasteful number, since it uses less digits than its factorization.

15998864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 903 (or 897 counting only the distinct ones).

The product of its digits is 622080, while the sum is 50.

The square root of 15998864 is about 3999.8579974794. The cubic root of 15998864 is about 251.9782462115.

The spelling of 15998864 in words is "fifteen million, nine hundred ninety-eight thousand, eight hundred sixty-four".