20907687 has 4 divisors (see below), whose sum is σ = 27876920. Its totient is φ = 13938456.

The previous prime is 20907673. The next prime is 20907697. The reversal of 20907687 is 78670902.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 20907687 - 2²³ = 12519079 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20907647) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3484612 + ... + 3484617.

It is an arithmetic number, because the mean of its divisors is an integer number (6969230).

Almost surely, 2^20907687 is an apocalyptic number.

20907687 is a deficient number, since it is larger than the sum of its proper divisors (6969233).

20907687 is an equidigital number, since it uses as much as digits as its factorization.

20907687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6969232.

The product of its (nonzero) digits is 42336, while the sum is 39.

The square root of 20907687 is about 4572.4924275498. The cubic root of 20907687 is about 275.4875626108.

The spelling of 20907687 in words is "twenty million, nine hundred seven thousand, six hundred eighty-seven".