90810857 has 2 divisors, whose sum is σ = 90810858. Its totient is φ = 90810856.

The previous prime is 90810851. The next prime is 90810871. The reversal of 90810857 is 75801809.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 86192656 + 4618201 = 9284^2 + 2149^2 .

It is an emirp because it is prime and its reverse (75801809) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 90810857 - 2¹⁰ = 90809833 is a prime.

It is a super-2 number, since 2×90810857² = 16493223498148898, 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 90810857.

It is not a weakly prime, because it can be changed into another prime (90810851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45405428 + 45405429.

It is an arithmetic number, because the mean of its divisors is an integer number (45405429).

Almost surely, 2^90810857 is an apocalyptic number.

It is an amenable number.

90810857 is a deficient number, since it is larger than the sum of its proper divisors (1).

90810857 is an equidigital number, since it uses as much as digits as its factorization.

90810857 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20160, while the sum is 38.

The square root of 90810857 is about 9529.4730704273. The cubic root of 90810857 is about 449.4822968171.

The spelling of 90810857 in words is "ninety million, eight hundred ten thousand, eight hundred fifty-seven".