90712721 has 8 divisors (see below), whose sum is σ = 99279264. Its totient is φ = 82199520.

The previous prime is 90712717. The next prime is 90712729. The reversal of 90712721 is 12721709.

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 90712721 - 2² = 90712717 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (90712729) 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, 9731 + ... + 16616.

It is an arithmetic number, because the mean of its divisors is an integer number (12409908).

Almost surely, 2^90712721 is an apocalyptic number.

It is an amenable number.

90712721 is a deficient number, since it is larger than the sum of its proper divisors (8566543).

90712721 is a wasteful number, since it uses less digits than its factorization.

90712721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26671.

The product of its (nonzero) digits is 1764, while the sum is 29.

The square root of 90712721 is about 9524.3226005843. The cubic root of 90712721 is about 449.3203253848.

The spelling of 90712721 in words is "ninety million, seven hundred twelve thousand, seven hundred twenty-one".