20555631 has 12 divisors (see below), whose sum is σ = 29810352. Its totient is φ = 13648896.

The previous prime is 20555599. The next prime is 20555641. The reversal of 20555631 is 13655502.

20555631 is a `hidden beast` number, since 20 + 5 + 5 + 5 + 631 = 666.

It is not a de Polignac number, because 20555631 - 2⁵ = 20555599 is a prime.

It is a super-2 number, since 2×20555631² = 845067931616322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20555595 and 20555604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20555641) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2131 + ... + 6756.

It is an arithmetic number, because the mean of its divisors is an integer number (2484196).

Almost surely, 2^20555631 is an apocalyptic number.

20555631 is a deficient number, since it is larger than the sum of its proper divisors (9254721).

20555631 is a wasteful number, since it uses less digits than its factorization.

20555631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9150 (or 9147 counting only the distinct ones).

The product of its (nonzero) digits is 4500, while the sum is 27.

The square root of 20555631 is about 4533.8318230830. The cubic root of 20555631 is about 273.9325272972.

The spelling of 20555631 in words is "twenty million, five hundred fifty-five thousand, six hundred thirty-one".