20901631 has 2 divisors, whose sum is σ = 20901632. Its totient is φ = 20901630.

The previous prime is 20901607. The next prime is 20901637. The reversal of 20901631 is 13610902.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20901631 - 2⁵ = 20901599 is a prime.

It is a super-2 number, since 2×20901631² = 873756356920322, which contains 22 as substring.

It is a plaindrome in base 16.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20901637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10450815 + 10450816.

It is an arithmetic number, because the mean of its divisors is an integer number (10450816).

Almost surely, 2^20901631 is an apocalyptic number.

20901631 is a deficient number, since it is larger than the sum of its proper divisors (1).

20901631 is an equidigital number, since it uses as much as digits as its factorization.

20901631 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 324, while the sum is 22.

The square root of 20901631 is about 4571.8301587001. The cubic root of 20901631 is about 275.4609613295.

It can be divided in two parts, 2090 and 1631, that added together give a square (3721 = 61²).

The spelling of 20901631 in words is "twenty million, nine hundred one thousand, six hundred thirty-one".