15920987 has 4 divisors (see below), whose sum is σ = 16026576. Its totient is φ = 15815400.

The previous prime is 15920981. The next prime is 15920999. The reversal of 15920987 is 78902951.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 78902951 = 61 ⋅1293491.

It is a cyclic number.

It is not a de Polignac number, because 15920987 - 2⁶ = 15920923 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15920981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 52568 + ... + 52869.

It is an arithmetic number, because the mean of its divisors is an integer number (4006644).

Almost surely, 2^15920987 is an apocalyptic number.

15920987 is a deficient number, since it is larger than the sum of its proper divisors (105589).

15920987 is a wasteful number, since it uses less digits than its factorization.

15920987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105588.

The product of its (nonzero) digits is 45360, while the sum is 41.

The square root of 15920987 is about 3990.1111513340. Note that the first 4 decimals coincide. The cubic root of 15920987 is about 251.5687330503.

The spelling of 15920987 in words is "fifteen million, nine hundred twenty thousand, nine hundred eighty-seven".