221020758961 has 2 divisors, whose sum is σ = 221020758962. Its totient is φ = 221020758960.

The previous prime is 221020758911. The next prime is 221020758967. The reversal of 221020758961 is 169857020122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 219357342736 + 1663416225 = 468356^2 + 40785^2 .

It is a cyclic number.

It is not a de Polignac number, because 221020758961 - 2⁹ = 221020758449 is a prime.

It is not a weakly prime, because it can be changed into another prime (221020758967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110510379480 + 110510379481.

It is an arithmetic number, because the mean of its divisors is an integer number (110510379481).

Almost surely, 2^221020758961 is an apocalyptic number.

It is an amenable number.

221020758961 is a deficient number, since it is larger than the sum of its proper divisors (1).

221020758961 is an equidigital number, since it uses as much as digits as its factorization.

221020758961 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 120960, while the sum is 43.

The spelling of 221020758961 in words is "two hundred twenty-one billion, twenty million, seven hundred fifty-eight thousand, nine hundred sixty-one".