23591372721 has 16 divisors (see below), whose sum is σ = 35953741824. Its totient is φ = 13478915664.

The previous prime is 23591372689. The next prime is 23591372729. The reversal of 23591372721 is 12727319532.

It is a happy number.

It is not a de Polignac number, because 23591372721 - 2⁵ = 23591372689 is a prime.

It is a super-2 number, since 2×23591372721² (a number of 22 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (23591372729) 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, 85170 + ... + 233316.

It is an arithmetic number, because the mean of its divisors is an integer number (2247108864).

Almost surely, 2^23591372721 is an apocalyptic number.

23591372721 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

23591372721 is a deficient number, since it is larger than the sum of its proper divisors (12362369103).

23591372721 is a wasteful number, since it uses less digits than its factorization.

23591372721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155740.

The product of its digits is 158760, while the sum is 42.

The spelling of 23591372721 in words is "twenty-three billion, five hundred ninety-one million, three hundred seventy-two thousand, seven hundred twenty-one".