20937987 has 32 divisors (see below), whose sum is σ = 35750400. Its totient is φ = 11863584.

The previous prime is 20937953. The next prime is 20938013. The reversal of 20937987 is 78973902.

It is not a de Polignac number, because 20937987 - 2⁷ = 20937859 is a prime.

It is a super-2 number, since 2×20937987² = 876798599224338, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20932987) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 25873 + ... + 26669.

It is an arithmetic number, because the mean of its divisors is an integer number (1117200).

Almost surely, 2^20937987 is an apocalyptic number.

20937987 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

20937987 is a deficient number, since it is larger than the sum of its proper divisors (14812413).

20937987 is a wasteful number, since it uses less digits than its factorization.

20937987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 952 (or 946 counting only the distinct ones).

The product of its (nonzero) digits is 190512, while the sum is 45.

The square root of 20937987 is about 4575.8045194261. The cubic root of 20937987 is about 275.6205797801.

The spelling of 20937987 in words is "twenty million, nine hundred thirty-seven thousand, nine hundred eighty-seven".