20631556 has 12 divisors (see below), whose sum is σ = 39387600. Its totient is φ = 9377960.

The previous prime is 20631547. The next prime is 20631563. The reversal of 20631556 is 65513602.

It is a super-2 number, since 2×20631556² = 851322205962272, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 234406 + ... + 234493.

It is an arithmetic number, because the mean of its divisors is an integer number (3282300).

Almost surely, 2^20631556 is an apocalyptic number.

It is an amenable number.

20631556 is a deficient number, since it is larger than the sum of its proper divisors (18756044).

20631556 is a wasteful number, since it uses less digits than its factorization.

20631556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 468914 (or 468912 counting only the distinct ones).

The product of its (nonzero) digits is 5400, while the sum is 28.

The square root of 20631556 is about 4542.1972656414. The cubic root of 20631556 is about 274.2693818297.

The spelling of 20631556 in words is "twenty million, six hundred thirty-one thousand, five hundred fifty-six".