90509493721 has 16 divisors (see below), whose sum is σ = 95423822208. Its totient is φ = 85738262400.

The previous prime is 90509493709. The next prime is 90509493731. The reversal of 90509493721 is 12739490509.

It is a cyclic number.

It is not a de Polignac number, because 90509493721 - 2⁵ = 90509493689 is a prime.

It is not an unprimeable number, because it can be changed into a prime (90509493731) 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 in 15 ways as a sum of consecutive naturals, for example, 403341 + ... + 586261.

It is an arithmetic number, because the mean of its divisors is an integer number (5963988888).

Almost surely, 2^90509493721 is an apocalyptic number.

It is an amenable number.

90509493721 is a deficient number, since it is larger than the sum of its proper divisors (4914328487).

90509493721 is a wasteful number, since it uses less digits than its factorization.

90509493721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 183312.

The product of its (nonzero) digits is 612360, while the sum is 49.

The spelling of 90509493721 in words is "ninety billion, five hundred nine million, four hundred ninety-three thousand, seven hundred twenty-one".