90245721 has 8 divisors (see below), whose sum is σ = 125559360. Its totient is φ = 57547952.

The previous prime is 90245713. The next prime is 90245723. The reversal of 90245721 is 12754209.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 90245721 - 2³ = 90245713 is a prime.

It is not an unprimeable number, because it can be changed into a prime (90245723) 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 in 7 ways as a sum of consecutive naturals, for example, 653886 + ... + 654023.

It is an arithmetic number, because the mean of its divisors is an integer number (15694920).

Almost surely, 2^90245721 is an apocalyptic number.

It is an amenable number.

90245721 is a deficient number, since it is larger than the sum of its proper divisors (35313639).

90245721 is a wasteful number, since it uses less digits than its factorization.

90245721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1307935.

The product of its (nonzero) digits is 5040, while the sum is 30.

The square root of 90245721 is about 9499.7747868042. The cubic root of 90245721 is about 448.5479467364.

The spelling of 90245721 in words is "ninety million, two hundred forty-five thousand, seven hundred twenty-one".