90864181 has 2 divisors, whose sum is σ = 90864182. Its totient is φ = 90864180.

The previous prime is 90864157. The next prime is 90864211. The reversal of 90864181 is 18146809.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 77968900 + 12895281 = 8830^2 + 3591^2 .

It is a cyclic number.

It is not a de Polignac number, because 90864181 - 2¹⁵ = 90831413 is a prime.

It is a super-2 number, since 2×90864181² = 16512598777601522, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 90864181.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (90864121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45432090 + 45432091.

It is an arithmetic number, because the mean of its divisors is an integer number (45432091).

Almost surely, 2^90864181 is an apocalyptic number.

It is an amenable number.

90864181 is a deficient number, since it is larger than the sum of its proper divisors (1).

90864181 is an equidigital number, since it uses as much as digits as its factorization.

90864181 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13824, while the sum is 37.

The square root of 90864181 is about 9532.2705060232. The cubic root of 90864181 is about 449.5702580475.

The spelling of 90864181 in words is "ninety million, eight hundred sixty-four thousand, one hundred eighty-one".