90205657 has 2 divisors, whose sum is σ = 90205658. Its totient is φ = 90205656.

The previous prime is 90205639. The next prime is 90205669. The reversal of 90205657 is 75650209.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 78481881 + 11723776 = 8859^2 + 3424^2 .

It is an emirp because it is prime and its reverse (75650209) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 90205657 - 2¹¹ = 90203609 is a prime.

It is not a weakly prime, because it can be changed into another prime (90205637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45102828 + 45102829.

It is an arithmetic number, because the mean of its divisors is an integer number (45102829).

Almost surely, 2^90205657 is an apocalyptic number.

It is an amenable number.

90205657 is a deficient number, since it is larger than the sum of its proper divisors (1).

90205657 is an equidigital number, since it uses as much as digits as its factorization.

90205657 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18900, while the sum is 34.

The square root of 90205657 is about 9497.6658711496. The cubic root of 90205657 is about 448.4815602651.

The spelling of 90205657 in words is "ninety million, two hundred five thousand, six hundred fifty-seven".