21220022977 has 2 divisors, whose sum is σ = 21220022978. Its totient is φ = 21220022976.

The previous prime is 21220022959. The next prime is 21220022983. The reversal of 21220022977 is 77922002212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18925229761 + 2294793216 = 137569^2 + 47904^2 .

It is a cyclic number.

It is not a de Polignac number, because 21220022977 - 2¹⁹ = 21219498689 is a prime.

It is not a weakly prime, because it can be changed into another prime (21220022077) 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, 10610011488 + 10610011489.

It is an arithmetic number, because the mean of its divisors is an integer number (10610011489).

Almost surely, 2^21220022977 is an apocalyptic number.

It is an amenable number.

21220022977 is a deficient number, since it is larger than the sum of its proper divisors (1).

21220022977 is an equidigital number, since it uses as much as digits as its factorization.

21220022977 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 14112, while the sum is 34.

The spelling of 21220022977 in words is "twenty-one billion, two hundred twenty million, twenty-two thousand, nine hundred seventy-seven".