90857321 has 2 divisors, whose sum is σ = 90857322. Its totient is φ = 90857320.

The previous prime is 90857309. The next prime is 90857329. The reversal of 90857321 is 12375809.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 72675625 + 18181696 = 8525^2 + 4264^2 .

It is a cyclic number.

It is not a de Polignac number, because 90857321 - 2¹⁸ = 90595177 is a prime.

It is a Chen prime.

It is equal to p_5263847 and since 90857321 and 5263847 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (90857329) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45428660 + 45428661.

It is an arithmetic number, because the mean of its divisors is an integer number (45428661).

Almost surely, 2^90857321 is an apocalyptic number.

It is an amenable number.

90857321 is a deficient number, since it is larger than the sum of its proper divisors (1).

90857321 is an equidigital number, since it uses as much as digits as its factorization.

90857321 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15120, while the sum is 35.

The square root of 90857321 is about 9531.9106689058. The cubic root of 90857321 is about 449.5589439831.

The spelling of 90857321 in words is "ninety million, eight hundred fifty-seven thousand, three hundred twenty-one".