89999999999721 has 32 divisors (see below), whose sum is σ = 154879000800000. Its totient is φ = 50585480087040.

The previous prime is 89999999999677. The next prime is 89999999999753. The reversal of 89999999999721 is 12799999999998.

It is not a de Polignac number, because 89999999999721 - 2⁹ = 89999999999209 is a prime.

It is not an unprimeable number, because it can be changed into a prime (89999999949721) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3903189096 + ... + 3903212153.

It is an arithmetic number, because the mean of its divisors is an integer number (4839968775000).

Almost surely, 2^{89999999999721} is an apocalyptic number.

It is an amenable number.

89999999999721 is a deficient number, since it is larger than the sum of its proper divisors (64879000800279).

89999999999721 is a wasteful number, since it uses less digits than its factorization.

89999999999721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7806401326 (or 7806401320 counting only the distinct ones).

The product of its digits is 390519852912, while the sum is 108.

The spelling of 89999999999721 in words is "eighty-nine trillion, nine hundred ninety-nine billion, nine hundred ninety-nine million, nine hundred ninety-nine thousand, seven hundred twenty-one".