15399840 has 48 divisors (see below), whose sum is σ = 48511008. Its totient is φ = 4106496.

The previous prime is 15399833. The next prime is 15399851. The reversal of 15399840 is 4899351.

It is a tau number, because it is divible by the number of its divisors (48).

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, 15562 + ... + 16521.

It is an arithmetic number, because the mean of its divisors is an integer number (1010646).

Almost surely, 2^15399840 is an apocalyptic number.

15399840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

15399840 is an abundant number, since it is smaller than the sum of its proper divisors (33111168).

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

15399840 is a wasteful number, since it uses less digits than its factorization.

15399840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32101 (or 32093 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 39.

The square root of 15399840 is about 3924.2629881291. The cubic root of 15399840 is about 248.7933318450.

The spelling of 15399840 in words is "fifteen million, three hundred ninety-nine thousand, eight hundred forty".