22997981 has 2 divisors, whose sum is σ = 22997982. Its totient is φ = 22997980.

The previous prime is 22997971. The next prime is 22997983. The reversal of 22997981 is 18979922.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14784025 + 8213956 = 3845^2 + 2866^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-22997981 is a prime.

It is a super-2 number, since 2×22997981² = 1057814260152722, which contains 22 as substring.

Together with 22997983, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (22997983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11498990 + 11498991.

It is an arithmetic number, because the mean of its divisors is an integer number (11498991).

Almost surely, 2^22997981 is an apocalyptic number.

It is an amenable number.

22997981 is a deficient number, since it is larger than the sum of its proper divisors (1).

22997981 is an equidigital number, since it uses as much as digits as its factorization.

22997981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 163296, while the sum is 47.

The square root of 22997981 is about 4795.6210233921. The cubic root of 22997981 is about 284.3783763396.

The spelling of 22997981 in words is "twenty-two million, nine hundred ninety-seven thousand, nine hundred eighty-one".