88721721 has 24 divisors (see below), whose sum is σ = 144318720. Its totient is φ = 52034400.

The previous prime is 88721713. The next prime is 88721747. The reversal of 88721721 is 12712788.

It is a happy number.

It is not a de Polignac number, because 88721721 - 2³ = 88721713 is a prime.

It is not an unprimeable number, because it can be changed into a prime (88721761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11386 + ... + 17523.

It is an arithmetic number, because the mean of its divisors is an integer number (6013280).

Almost surely, 2^88721721 is an apocalyptic number.

It is an amenable number.

88721721 is a deficient number, since it is larger than the sum of its proper divisors (55596999).

88721721 is a wasteful number, since it uses less digits than its factorization.

88721721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28957 (or 28954 counting only the distinct ones).

The product of its digits is 12544, while the sum is 36.

The square root of 88721721 is about 9419.2208276481. The cubic root of 88721721 is about 446.0086885905.

The spelling of 88721721 in words is "eighty-eight million, seven hundred twenty-one thousand, seven hundred twenty-one".