90197621 has 2 divisors, whose sum is σ = 90197622. Its totient is φ = 90197620.

The previous prime is 90197587. The next prime is 90197629. The reversal of 90197621 is 12679109.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 45495025 + 44702596 = 6745^2 + 6686^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-90197621 is a prime.

It is a super-2 number, since 2×90197621² = 16271221668119282, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (90197629) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45098810 + 45098811.

It is an arithmetic number, because the mean of its divisors is an integer number (45098811).

Almost surely, 2^90197621 is an apocalyptic number.

It is an amenable number.

90197621 is a deficient number, since it is larger than the sum of its proper divisors (1).

90197621 is an equidigital number, since it uses as much as digits as its factorization.

90197621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6804, while the sum is 35.

The square root of 90197621 is about 9497.2428104161. The cubic root of 90197621 is about 448.4682421615.

The spelling of 90197621 in words is "ninety million, one hundred ninety-seven thousand, six hundred twenty-one".