22279921 has 2 divisors, whose sum is σ = 22279922. Its totient is φ = 22279920.

The previous prime is 22279919. The next prime is 22279931. The reversal of 22279921 is 12997222.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 22278400 + 1521 = 4720^2 + 39^2 .

It is a cyclic number.

It is not a de Polignac number, because 22279921 - 2¹ = 22279919 is a prime.

Together with 22279919, it forms a pair of twin primes.

It is equal to p_1405699 and since 22279921 and 1405699 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (22279931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11139960 + 11139961.

It is an arithmetic number, because the mean of its divisors is an integer number (11139961).

Almost surely, 2^22279921 is an apocalyptic number.

It is an amenable number.

22279921 is a deficient number, since it is larger than the sum of its proper divisors (1).

22279921 is an equidigital number, since it uses as much as digits as its factorization.

22279921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9072, while the sum is 34.

The square root of 22279921 is about 4720.1611201314. The cubic root of 22279921 is about 281.3873366467.

The spelling of 22279921 in words is "twenty-two million, two hundred seventy-nine thousand, nine hundred twenty-one".