21977023 has 2 divisors, whose sum is σ = 21977024. Its totient is φ = 21977022.

The previous prime is 21976979. The next prime is 21977027. The reversal of 21977023 is 32077912.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21977023 - 2⁹ = 21976511 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21977027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10988511 + 10988512.

It is an arithmetic number, because the mean of its divisors is an integer number (10988512).

Almost surely, 2^21977023 is an apocalyptic number.

21977023 is a deficient number, since it is larger than the sum of its proper divisors (1).

21977023 is an equidigital number, since it uses as much as digits as its factorization.

21977023 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5292, while the sum is 31.

The square root of 21977023 is about 4687.9657635269. The cubic root of 21977023 is about 280.1063499071.

The spelling of 21977023 in words is "twenty-one million, nine hundred seventy-seven thousand, twenty-three".