22021957 has 2 divisors, whose sum is σ = 22021958. Its totient is φ = 22021956.

The previous prime is 22021943. The next prime is 22021963. The reversal of 22021957 is 75912022.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16112196 + 5909761 = 4014^2 + 2431^2 .

It is a cyclic number.

It is not a de Polignac number, because 22021957 - 2⁷ = 22021829 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (22021357) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11010978 + 11010979.

It is an arithmetic number, because the mean of its divisors is an integer number (11010979).

Almost surely, 2^22021957 is an apocalyptic number.

It is an amenable number.

22021957 is a deficient number, since it is larger than the sum of its proper divisors (1).

22021957 is an equidigital number, since it uses as much as digits as its factorization.

22021957 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2520, while the sum is 28.

The square root of 22021957 is about 4692.7558001669. The cubic root of 22021957 is about 280.2971208245.

Adding to 22021957 its reverse (75912022), we get a palindrome (97933979).

The spelling of 22021957 in words is "twenty-two million, twenty-one thousand, nine hundred fifty-seven".