90061921 has 2 divisors, whose sum is σ = 90061922. Its totient is φ = 90061920.

The previous prime is 90061891. The next prime is 90061927. The reversal of 90061921 is 12916009.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 87628321 + 2433600 = 9361^2 + 1560^2 .

It is a cyclic number.

It is not a de Polignac number, because 90061921 - 2⁹ = 90061409 is a prime.

It is a super-2 number, since 2×90061921² = 16222299228420482, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 90061921.

It is not a weakly prime, because it can be changed into another prime (90061927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45030960 + 45030961.

It is an arithmetic number, because the mean of its divisors is an integer number (45030961).

Almost surely, 2^90061921 is an apocalyptic number.

It is an amenable number.

90061921 is a deficient number, since it is larger than the sum of its proper divisors (1).

90061921 is an equidigital number, since it uses as much as digits as its factorization.

90061921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 972, while the sum is 28.

The square root of 90061921 is about 9490.0959426130. The cubic root of 90061921 is about 448.2432263032.

The spelling of 90061921 in words is "ninety million, sixty-one thousand, nine hundred twenty-one".