20331987 has 16 divisors (see below), whose sum is σ = 30203040. Its totient is φ = 12079872.

The previous prime is 20331967. The next prime is 20331989. The reversal of 20331987 is 78913302.

It is not a de Polignac number, because 20331987 - 2¹⁵ = 20299219 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20331989) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7858 + ... + 10119.

It is an arithmetic number, because the mean of its divisors is an integer number (1887690).

Almost surely, 2^20331987 is an apocalyptic number.

20331987 is a deficient number, since it is larger than the sum of its proper divisors (9871053).

20331987 is a wasteful number, since it uses less digits than its factorization.

20331987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18022.

The product of its (nonzero) digits is 9072, while the sum is 33.

The square root of 20331987 is about 4509.1004646160. The cubic root of 20331987 is about 272.9354461007.

The spelling of 20331987 in words is "twenty million, three hundred thirty-one thousand, nine hundred eighty-seven".