22687891 has 2 divisors, whose sum is σ = 22687892. Its totient is φ = 22687890.

The previous prime is 22687879. The next prime is 22687897. The reversal of 22687891 is 19878622.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 22687891 - 2⁵ = 22687859 is a prime.

It is not a weakly prime, because it can be changed into another prime (22687897) 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, 11343945 + 11343946.

It is an arithmetic number, because the mean of its divisors is an integer number (11343946).

Almost surely, 2^22687891 is an apocalyptic number.

22687891 is the 3013-rd centered pentagonal number.

22687891 is a deficient number, since it is larger than the sum of its proper divisors (1).

22687891 is an equidigital number, since it uses as much as digits as its factorization.

22687891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 96768, while the sum is 43.

The square root of 22687891 is about 4763.1807649931. The cubic root of 22687891 is about 283.0944633398.

The spelling of 22687891 in words is "twenty-two million, six hundred eighty-seven thousand, eight hundred ninety-one".