90749521 has 2 divisors, whose sum is σ = 90749522. Its totient is φ = 90749520.

The previous prime is 90749471. The next prime is 90749531. The reversal of 90749521 is 12594709.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 90345025 + 404496 = 9505^2 + 636^2 .

It is a cyclic number.

It is not a de Polignac number, because 90749521 - 2²³ = 82360913 is a prime.

It is not a weakly prime, because it can be changed into another prime (90749531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45374760 + 45374761.

It is an arithmetic number, because the mean of its divisors is an integer number (45374761).

Almost surely, 2^90749521 is an apocalyptic number.

It is an amenable number.

90749521 is a deficient number, since it is larger than the sum of its proper divisors (1).

90749521 is an equidigital number, since it uses as much as digits as its factorization.

90749521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 22680, while the sum is 37.

The square root of 90749521 is about 9526.2543006157. The cubic root of 90749521 is about 449.3810767044.

The spelling of 90749521 in words is "ninety million, seven hundred forty-nine thousand, five hundred twenty-one".