88665721 has 4 divisors (see below), whose sum is σ = 88691200. Its totient is φ = 88640244.

The previous prime is 88665719. The next prime is 88665749. The reversal of 88665721 is 12756688.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 88665721 - 2¹ = 88665719 is a prime.

It is a super-2 number, since 2×88665721² = 15723220160899682, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (88665791) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6501 + ... + 14818.

It is an arithmetic number, because the mean of its divisors is an integer number (22172800).

Almost surely, 2^88665721 is an apocalyptic number.

It is an amenable number.

88665721 is a deficient number, since it is larger than the sum of its proper divisors (25479).

88665721 is a wasteful number, since it uses less digits than its factorization.

88665721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25478.

The product of its digits is 161280, while the sum is 43.

The square root of 88665721 is about 9416.2477133941. The cubic root of 88665721 is about 445.9148305398.

The spelling of 88665721 in words is "eighty-eight million, six hundred sixty-five thousand, seven hundred twenty-one".