15991392 has 48 divisors (see below), whose sum is σ = 42284592. Its totient is φ = 5291520.

The previous prime is 15991387. The next prime is 15991397. The reversal of 15991392 is 29319951.

It is an interprime number because it is at equal distance from previous prime (15991387) and next prime (15991397).

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

It is a self number, because there is not a number n which added to its sum of digits gives 15991392.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15991397) 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, 14542 + ... + 15602.

It is an arithmetic number, because the mean of its divisors is an integer number (880929).

Almost surely, 2^15991392 is an apocalyptic number.

15991392 is a gapful number since it is divisible by the number (12) 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 15991392, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21142296).

15991392 is an abundant number, since it is smaller than the sum of its proper divisors (26293200).

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

15991392 is a wasteful number, since it uses less digits than its factorization.

15991392 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1231 (or 1223 counting only the distinct ones).

The product of its digits is 21870, while the sum is 39.

The square root of 15991392 is about 3998.9238552391. The cubic root of 15991392 is about 251.9390127043.

The spelling of 15991392 in words is "fifteen million, nine hundred ninety-one thousand, three hundred ninety-two".