90311621 has 2 divisors, whose sum is σ = 90311622. Its totient is φ = 90311620.

The previous prime is 90311603. The next prime is 90311651. The reversal of 90311621 is 12611309.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 82555396 + 7756225 = 9086^2 + 2785^2 .

It is a cyclic number.

It is not a de Polignac number, because 90311621 - 2¹⁴ = 90295237 is a prime.

It is a Chen prime.

It is equal to p_5234072 and since 90311621 and 5234072 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (90311651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45155810 + 45155811.

It is an arithmetic number, because the mean of its divisors is an integer number (45155811).

Almost surely, 2^90311621 is an apocalyptic number.

It is an amenable number.

90311621 is a deficient number, since it is larger than the sum of its proper divisors (1).

90311621 is an equidigital number, since it uses as much as digits as its factorization.

90311621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 324, while the sum is 23.

The square root of 90311621 is about 9503.2426571145. The cubic root of 90311621 is about 448.6571010072.

The spelling of 90311621 in words is "ninety million, three hundred eleven thousand, six hundred twenty-one".