20663631 has 24 divisors (see below), whose sum is σ = 31646160. Its totient is φ = 12969600.

The previous prime is 20663623. The next prime is 20663633. The reversal of 20663631 is 13636602.

20663631 is a `hidden beast` number, since 20 + 6 + 6 + 3 + 631 = 666.

It is not a de Polignac number, because 20663631 - 2³ = 20663623 is a prime.

It is a super-2 number, since 2×20663631² = 853971292208322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20663595 and 20663604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20663633) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9736 + ... + 11666.

It is an arithmetic number, because the mean of its divisors is an integer number (1318590).

Almost surely, 2^20663631 is an apocalyptic number.

20663631 is a deficient number, since it is larger than the sum of its proper divisors (10982529).

20663631 is a wasteful number, since it uses less digits than its factorization.

20663631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2007 (or 2004 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 27.

The square root of 20663631 is about 4545.7266745813. The cubic root of 20663631 is about 274.4114398739.

The spelling of 20663631 in words is "twenty million, six hundred sixty-three thousand, six hundred thirty-one".