15994881 has 16 divisors (see below), whose sum is σ = 27081600. Its totient is φ = 9139824.

The previous prime is 15994861. The next prime is 15994883. The reversal of 15994881 is 18849951.

It is not a de Polignac number, because 15994881 - 2¹⁴ = 15978497 is a prime.

It is a super-2 number, since 2×15994881² = 511672436408322, which contains 22 as substring.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (15994883) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 42126 + ... + 42503.

It is an arithmetic number, because the mean of its divisors is an integer number (1692600).

It is a Proth number, since it is equal to 3905 ⋅ 2¹² + 1 and 3905 < 2¹².

Almost surely, 2^15994881 is an apocalyptic number.

It is an amenable number.

15994881 is a deficient number, since it is larger than the sum of its proper divisors (11086719).

15994881 is an equidigital number, since it uses as much as digits as its factorization.

15994881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84645 (or 84639 counting only the distinct ones).

The product of its digits is 103680, while the sum is 45.

The square root of 15994881 is about 3999.3600738118. The cubic root of 15994881 is about 251.9573340465.

The spelling of 15994881 in words is "fifteen million, nine hundred ninety-four thousand, eight hundred eighty-one".