90415621 has 2 divisors, whose sum is σ = 90415622. Its totient is φ = 90415620.

The previous prime is 90415583. The next prime is 90415631. The reversal of 90415621 is 12651409.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 81180100 + 9235521 = 9010^2 + 3039^2 .

It is a cyclic number.

It is not a de Polignac number, because 90415621 - 2¹¹ = 90413573 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 90415621.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (90415631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45207810 + 45207811.

It is an arithmetic number, because the mean of its divisors is an integer number (45207811).

Almost surely, 2^90415621 is an apocalyptic number.

It is an amenable number.

90415621 is a deficient number, since it is larger than the sum of its proper divisors (1).

90415621 is an equidigital number, since it uses as much as digits as its factorization.

90415621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 90415621 is about 9508.7128992309. The cubic root of 90415621 is about 448.8292547071.

The spelling of 90415621 in words is "ninety million, four hundred fifteen thousand, six hundred twenty-one".