22139581 has 2 divisors, whose sum is σ = 22139582. Its totient is φ = 22139580.

The previous prime is 22139569. The next prime is 22139591. The reversal of 22139581 is 18593122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18567481 + 3572100 = 4309^2 + 1890^2 .

It is a cyclic number.

It is not a de Polignac number, because 22139581 - 2²³ = 13750973 is a prime.

It is a super-2 number, since 2×22139581² = 980322093711122, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (22139521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11069790 + 11069791.

It is an arithmetic number, because the mean of its divisors is an integer number (11069791).

Almost surely, 2^22139581 is an apocalyptic number.

It is an amenable number.

22139581 is a deficient number, since it is larger than the sum of its proper divisors (1).

22139581 is an equidigital number, since it uses as much as digits as its factorization.

22139581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4320, while the sum is 31.

The square root of 22139581 is about 4705.2716180897. The cubic root of 22139581 is about 280.7952773196.

The spelling of 22139581 in words is "twenty-two million, one hundred thirty-nine thousand, five hundred eighty-one".