20865087 has 16 divisors (see below), whose sum is σ = 31008000. Its totient is φ = 13866552.

The previous prime is 20865083. The next prime is 20865109. The reversal of 20865087 is 78056802.

It is not a de Polignac number, because 20865087 - 2² = 20865083 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20865083) 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, 9214 + ... + 11252.

It is an arithmetic number, because the mean of its divisors is an integer number (1938000).

Almost surely, 2^20865087 is an apocalyptic number.

20865087 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

20865087 is a deficient number, since it is larger than the sum of its proper divisors (10142913).

20865087 is a wasteful number, since it uses less digits than its factorization.

20865087 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2427 (or 2421 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 36.

The square root of 20865087 is about 4567.8317613502. The cubic root of 20865087 is about 275.3003308388.

The spelling of 20865087 in words is "twenty million, eight hundred sixty-five thousand, eighty-seven".