90437621 has 2 divisors, whose sum is σ = 90437622. Its totient is φ = 90437620.

The previous prime is 90437609. The next prime is 90437623. The reversal of 90437621 is 12673409.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 57547396 + 32890225 = 7586^2 + 5735^2 .

It is a cyclic number.

It is not a de Polignac number, because 90437621 - 2¹⁴ = 90421237 is a prime.

Together with 90437623, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (90437623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45218810 + 45218811.

It is an arithmetic number, because the mean of its divisors is an integer number (45218811).

Almost surely, 2^90437621 is an apocalyptic number.

It is an amenable number.

90437621 is a deficient number, since it is larger than the sum of its proper divisors (1).

90437621 is an equidigital number, since it uses as much as digits as its factorization.

90437621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9072, while the sum is 32.

The square root of 90437621 is about 9509.8696626189. The cubic root of 90437621 is about 448.8656549173.

The spelling of 90437621 in words is "ninety million, four hundred thirty-seven thousand, six hundred twenty-one".