20538631 has 2 divisors, whose sum is σ = 20538632. Its totient is φ = 20538630.

The previous prime is 20538611. The next prime is 20538643. The reversal of 20538631 is 13683502.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20538631 - 2⁷ = 20538503 is a prime.

It is a super-2 number, since 2×20538631² = 843670726708322, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20538631.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20538611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10269315 + 10269316.

It is an arithmetic number, because the mean of its divisors is an integer number (10269316).

Almost surely, 2^20538631 is an apocalyptic number.

20538631 is a deficient number, since it is larger than the sum of its proper divisors (1).

20538631 is an equidigital number, since it uses as much as digits as its factorization.

20538631 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 20538631 is about 4531.9566414519. The cubic root of 20538631 is about 273.8569902123.

The spelling of 20538631 in words is "twenty million, five hundred thirty-eight thousand, six hundred thirty-one".