90553721 has 2 divisors, whose sum is σ = 90553722. Its totient is φ = 90553720.

The previous prime is 90553711. The next prime is 90553741. The reversal of 90553721 is 12735509.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 90535225 + 18496 = 9515^2 + 136^2 .

It is a cyclic number.

It is not a de Polignac number, because 90553721 - 2²⁶ = 23444857 is a prime.

It is not a weakly prime, because it can be changed into another prime (90553711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45276860 + 45276861.

It is an arithmetic number, because the mean of its divisors is an integer number (45276861).

Almost surely, 2^90553721 is an apocalyptic number.

It is an amenable number.

90553721 is a deficient number, since it is larger than the sum of its proper divisors (1).

90553721 is an equidigital number, since it uses as much as digits as its factorization.

90553721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9450, while the sum is 32.

The square root of 90553721 is about 9515.9718894078. The cubic root of 90553721 is about 449.0576510415.

The spelling of 90553721 in words is "ninety million, five hundred fifty-three thousand, seven hundred twenty-one".