20211131 has 2 divisors, whose sum is σ = 20211132. Its totient is φ = 20211130.

The previous prime is 20211127. The next prime is 20211157. The reversal of 20211131 is 13111202.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20211131 - 2² = 20211127 is a prime.

It is a super-2 number, since 2×20211131² = 816979632598322, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20211031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10105565 + 10105566.

It is an arithmetic number, because the mean of its divisors is an integer number (10105566).

Almost surely, 2^20211131 is an apocalyptic number.

20211131 is a deficient number, since it is larger than the sum of its proper divisors (1).

20211131 is an equidigital number, since it uses as much as digits as its factorization.

20211131 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12, while the sum is 11.

The square root of 20211131 is about 4495.6791478040. The cubic root of 20211131 is about 272.3935830019.

Adding to 20211131 its reverse (13111202), we get a palindrome (33322333).

The spelling of 20211131 in words is "twenty million, two hundred eleven thousand, one hundred thirty-one".