90994518521 has 2 divisors, whose sum is σ = 90994518522. Its totient is φ = 90994518520.

The previous prime is 90994518491. The next prime is 90994518533. The reversal of 90994518521 is 12581549909.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 63926042896 + 27068475625 = 252836^2 + 164525^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-90994518521 is a prime.

It is a super-2 number, since 2×90994518521² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (90994518221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45497259260 + 45497259261.

It is an arithmetic number, because the mean of its divisors is an integer number (45497259261).

Almost surely, 2^90994518521 is an apocalyptic number.

It is an amenable number.

90994518521 is a deficient number, since it is larger than the sum of its proper divisors (1).

90994518521 is an equidigital number, since it uses as much as digits as its factorization.

90994518521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1166400, while the sum is 53.

The spelling of 90994518521 in words is "ninety billion, nine hundred ninety-four million, five hundred eighteen thousand, five hundred twenty-one".