21020207922977 has 2 divisors, whose sum is σ = 21020207922978. Its totient is φ = 21020207922976.

The previous prime is 21020207922971. The next prime is 21020207923061. The reversal of 21020207922977 is 77922970202012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18133280705761 + 2886927217216 = 4258319^2 + 1699096^2 .

It is a cyclic number.

It is not a de Polignac number, because 21020207922977 - 2⁶ = 21020207922913 is a prime.

It is a super-2 number, since 2×21020207922977² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21020207922971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510103961488 + 10510103961489.

It is an arithmetic number, because the mean of its divisors is an integer number (10510103961489).

Almost surely, 2^{21020207922977} is an apocalyptic number.

It is an amenable number.

21020207922977 is a deficient number, since it is larger than the sum of its proper divisors (1).

21020207922977 is an equidigital number, since it uses as much as digits as its factorization.

21020207922977 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 889056, while the sum is 50.

The spelling of 21020207922977 in words is "twenty-one trillion, twenty billion, two hundred seven million, nine hundred twenty-two thousand, nine hundred seventy-seven".