15998440 has 32 divisors (see below), whose sum is σ = 36612000. Its totient is φ = 6289984.

The previous prime is 15998429. The next prime is 15998443. The reversal of 15998440 is 4489951.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 15998393 and 15998402.

It is not an unprimeable number, because it can be changed into a prime (15998443) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1030 + ... + 5749.

It is an arithmetic number, because the mean of its divisors is an integer number (1144125).

Almost surely, 2^15998440 is an apocalyptic number.

15998440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

15998440 is an abundant number, since it is smaller than the sum of its proper divisors (20613560).

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

15998440 is a wasteful number, since it uses less digits than its factorization.

15998440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6849 (or 6845 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 40.

The square root of 15998440 is about 3999.8049952466. The cubic root of 15998440 is about 251.9760202260.

The spelling of 15998440 in words is "fifteen million, nine hundred ninety-eight thousand, four hundred forty".