21112019977 has 2 divisors, whose sum is σ = 21112019978. Its totient is φ = 21112019976.

The previous prime is 21112019909. The next prime is 21112020011. The reversal of 21112019977 is 77991021112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17469173241 + 3642846736 = 132171^2 + 60356^2 .

It is a cyclic number.

It is not a de Polignac number, because 21112019977 - 2⁷ = 21112019849 is a prime.

It is not a weakly prime, because it can be changed into another prime (21172019977) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10556009988 + 10556009989.

It is an arithmetic number, because the mean of its divisors is an integer number (10556009989).

Almost surely, 2^21112019977 is an apocalyptic number.

It is an amenable number.

21112019977 is a deficient number, since it is larger than the sum of its proper divisors (1).

21112019977 is an equidigital number, since it uses as much as digits as its factorization.

21112019977 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15876, while the sum is 40.

The spelling of 21112019977 in words is "twenty-one billion, one hundred twelve million, nineteen thousand, nine hundred seventy-seven".