90543434521 has 2 divisors, whose sum is σ = 90543434522. Its totient is φ = 90543434520.

The previous prime is 90543434489. The next prime is 90543434551. The reversal of 90543434521 is 12543434509.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 67008499600 + 23534934921 = 258860^2 + 153411^2 .

It is a cyclic number.

It is not a de Polignac number, because 90543434521 - 2⁵ = 90543434489 is a prime.

It is a super-2 number, since 2×90543434521² (a number of 23 digits) contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is not a weakly prime, because it can be changed into another prime (90543434551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45271717260 + 45271717261.

It is an arithmetic number, because the mean of its divisors is an integer number (45271717261).

Almost surely, 2^90543434521 is an apocalyptic number.

It is an amenable number.

90543434521 is a deficient number, since it is larger than the sum of its proper divisors (1).

90543434521 is an equidigital number, since it uses as much as digits as its factorization.

90543434521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 259200, while the sum is 40.

The spelling of 90543434521 in words is "ninety billion, five hundred forty-three million, four hundred thirty-four thousand, five hundred twenty-one".