21930131 has 2 divisors, whose sum is σ = 21930132. Its totient is φ = 21930130.

The previous prime is 21930107. The next prime is 21930137. The reversal of 21930131 is 13103912.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21930131 - 2¹⁰ = 21929107 is a prime.

It is a super-2 number, since 2×21930131² = 961861291354322, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21930137) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10965065 + 10965066.

It is an arithmetic number, because the mean of its divisors is an integer number (10965066).

Almost surely, 2^21930131 is an apocalyptic number.

21930131 is a deficient number, since it is larger than the sum of its proper divisors (1).

21930131 is an equidigital number, since it uses as much as digits as its factorization.

21930131 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 162, while the sum is 20.

The square root of 21930131 is about 4682.9617764829. The cubic root of 21930131 is about 279.9069886644.

The spelling of 21930131 in words is "twenty-one million, nine hundred thirty thousand, one hundred thirty-one".