21867977 has 2 divisors, whose sum is σ = 21867978. Its totient is φ = 21867976.

The previous prime is 21867973. The next prime is 21867983. The reversal of 21867977 is 77976812.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14409616 + 7458361 = 3796^2 + 2731^2 .

It is a cyclic number.

It is not a de Polignac number, because 21867977 - 2² = 21867973 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21867973) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10933988 + 10933989.

It is an arithmetic number, because the mean of its divisors is an integer number (10933989).

Almost surely, 2^21867977 is an apocalyptic number.

It is an amenable number.

21867977 is a deficient number, since it is larger than the sum of its proper divisors (1).

21867977 is an equidigital number, since it uses as much as digits as its factorization.

21867977 is an evil number, because the sum of its binary digits is even.

The product of its digits is 296352, while the sum is 47.

The square root of 21867977 is about 4676.3208829164. The cubic root of 21867977 is about 279.6423025932.

The spelling of 21867977 in words is "twenty-one million, eight hundred sixty-seven thousand, nine hundred seventy-seven".