21790455017 has 2 divisors, whose sum is σ = 21790455018. Its totient is φ = 21790455016.

The previous prime is 21790454977. The next prime is 21790455053. The reversal of 21790455017 is 71055409712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21747105961 + 43349056 = 147469^2 + 6584^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21790455017 is a prime.

It is not a weakly prime, because it can be changed into another prime (21790455077) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10895227508 + 10895227509.

It is an arithmetic number, because the mean of its divisors is an integer number (10895227509).

Almost surely, 2^21790455017 is an apocalyptic number.

It is an amenable number.

21790455017 is a deficient number, since it is larger than the sum of its proper divisors (1).

21790455017 is an equidigital number, since it uses as much as digits as its factorization.

21790455017 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 88200, while the sum is 41.

The spelling of 21790455017 in words is "twenty-one billion, seven hundred ninety million, four hundred fifty-five thousand, seventeen".