21311202311977 has 2 divisors, whose sum is σ = 21311202311978. Its totient is φ = 21311202311976.

The previous prime is 21311202311953. The next prime is 21311202312223. The reversal of 21311202311977 is 77911320211312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20621598292201 + 689604019776 = 4541101^2 + 830424^2 .

It is a cyclic number.

It is not a de Polignac number, because 21311202311977 - 2²⁷ = 21311068094249 is a prime.

It is not a weakly prime, because it can be changed into another prime (21311202341977) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10655601155988 + 10655601155989.

It is an arithmetic number, because the mean of its divisors is an integer number (10655601155989).

Almost surely, 2^{21311202311977} is an apocalyptic number.

It is an amenable number.

21311202311977 is a deficient number, since it is larger than the sum of its proper divisors (1).

21311202311977 is an equidigital number, since it uses as much as digits as its factorization.

21311202311977 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 31752, while the sum is 40.

The spelling of 21311202311977 in words is "twenty-one trillion, three hundred eleven billion, two hundred two million, three hundred eleven thousand, nine hundred seventy-seven".