20356631 has 2 divisors, whose sum is σ = 20356632. Its totient is φ = 20356630.

The previous prime is 20356627. The next prime is 20356639. The reversal of 20356631 is 13665302.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20356631 - 2² = 20356627 is a prime.

It is a super-2 number, since 2×20356631² = 828784851340322, which contains 22 as substring.

It is a Sophie Germain prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20356631.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20356639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10178315 + 10178316.

It is an arithmetic number, because the mean of its divisors is an integer number (10178316).

Almost surely, 2^20356631 is an apocalyptic number.

20356631 is a deficient number, since it is larger than the sum of its proper divisors (1).

20356631 is an equidigital number, since it uses as much as digits as its factorization.

20356631 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3240, while the sum is 26.

The square root of 20356631 is about 4511.8323328776. The cubic root of 20356631 is about 273.0456747991.

The spelling of 20356631 in words is "twenty million, three hundred fifty-six thousand, six hundred thirty-one".