21202777913 has 2 divisors, whose sum is σ = 21202777914. Its totient is φ = 21202777912.

The previous prime is 21202777909. The next prime is 21202777919. The reversal of 21202777913 is 31977720212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15355422889 + 5847355024 = 123917^2 + 76468^2 .

It is a cyclic number.

It is not a de Polignac number, because 21202777913 - 2² = 21202777909 is a prime.

It is not a weakly prime, because it can be changed into another prime (21202777919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10601388956 + 10601388957.

It is an arithmetic number, because the mean of its divisors is an integer number (10601388957).

Almost surely, 2^21202777913 is an apocalyptic number.

It is an amenable number.

21202777913 is a deficient number, since it is larger than the sum of its proper divisors (1).

21202777913 is an equidigital number, since it uses as much as digits as its factorization.

21202777913 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 74088, while the sum is 41.

The spelling of 21202777913 in words is "twenty-one billion, two hundred two million, seven hundred seventy-seven thousand, nine hundred thirteen".