21927563197 has 2 divisors, whose sum is σ = 21927563198. Its totient is φ = 21927563196.

The previous prime is 21927563123. The next prime is 21927563209. The reversal of 21927563197 is 79136572912.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21650473881 + 277089316 = 147141^2 + 16646^2 .

It is a cyclic number.

It is not a de Polignac number, because 21927563197 - 2⁷ = 21927563069 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21927566197) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10963781598 + 10963781599.

It is an arithmetic number, because the mean of its divisors is an integer number (10963781599).

Almost surely, 2^21927563197 is an apocalyptic number.

It is an amenable number.

21927563197 is a deficient number, since it is larger than the sum of its proper divisors (1).

21927563197 is an equidigital number, since it uses as much as digits as its factorization.

21927563197 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1428840, while the sum is 52.

The spelling of 21927563197 in words is "twenty-one billion, nine hundred twenty-seven million, five hundred sixty-three thousand, one hundred ninety-seven".