89840721 has 16 divisors (see below), whose sum is σ = 127400000. Its totient is φ = 56153088.

The previous prime is 89840713. The next prime is 89840741. The reversal of 89840721 is 12704898.

It is not a de Polignac number, because 89840721 - 2³ = 89840713 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 89840721.

It is not an unprimeable number, because it can be changed into a prime (89840701) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2596 + ... + 13653.

It is an arithmetic number, because the mean of its divisors is an integer number (7962500).

Almost surely, 2^89840721 is an apocalyptic number.

It is an amenable number.

89840721 is a deficient number, since it is larger than the sum of its proper divisors (37559279).

89840721 is a wasteful number, since it uses less digits than its factorization.

89840721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16368.

The product of its (nonzero) digits is 32256, while the sum is 39.

The square root of 89840721 is about 9478.4345226414. The cubic root of 89840721 is about 447.8759505209.

The spelling of 89840721 in words is "eighty-nine million, eight hundred forty thousand, seven hundred twenty-one".