90646517021 has 2 divisors, whose sum is σ = 90646517022. Its totient is φ = 90646517020.

The previous prime is 90646517009. The next prime is 90646517041. The reversal of 90646517021 is 12071564609.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 85504192921 + 5142324100 = 292411^2 + 71710^2 .

It is a cyclic number.

It is not a de Polignac number, because 90646517021 - 2³⁰ = 89572775197 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 90646517021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (90646517041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45323258510 + 45323258511.

It is an arithmetic number, because the mean of its divisors is an integer number (45323258511).

Almost surely, 2^90646517021 is an apocalyptic number.

It is an amenable number.

90646517021 is a deficient number, since it is larger than the sum of its proper divisors (1).

90646517021 is an equidigital number, since it uses as much as digits as its factorization.

90646517021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 90720, while the sum is 41.

The spelling of 90646517021 in words is "ninety billion, six hundred forty-six million, five hundred seventeen thousand, twenty-one".