90215977 has 2 divisors, whose sum is σ = 90215978. Its totient is φ = 90215976.

The previous prime is 90215903. The next prime is 90215987. The reversal of 90215977 is 77951209.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 48497296 + 41718681 = 6964^2 + 6459^2 .

It is a cyclic number.

It is not a de Polignac number, because 90215977 - 2¹⁵ = 90183209 is a prime.

It is not a weakly prime, because it can be changed into another prime (90215987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45107988 + 45107989.

It is an arithmetic number, because the mean of its divisors is an integer number (45107989).

Almost surely, 2^90215977 is an apocalyptic number.

It is an amenable number.

90215977 is a deficient number, since it is larger than the sum of its proper divisors (1).

90215977 is an equidigital number, since it uses as much as digits as its factorization.

90215977 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 39690, while the sum is 40.

The square root of 90215977 is about 9498.2091469919. The cubic root of 90215977 is about 448.4986624934.

The spelling of 90215977 in words is "ninety million, two hundred fifteen thousand, nine hundred seventy-seven".