23351201721 has 15 divisors (see below), whose sum is σ = 34884713941. Its totient is φ = 15566550948.

The previous prime is 23351201719. The next prime is 23351201759. The reversal of 23351201721 is 12710215332.

The square root of 23351201721 is 152811.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 23351201721 - 2¹ = 23351201719 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (23351201021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 1366810 + ... + 1383788.

Almost surely, 2^23351201721 is an apocalyptic number.

23351201721 is the 152811-st square number.

23351201721 is the 76406-th centered octagonal number.

It is an amenable number.

23351201721 is a deficient number, since it is larger than the sum of its proper divisors (11533512220).

23351201721 is an frugal number, since it uses more digits than its factorization.

23351201721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33970 (or 16982 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 27.

The spelling of 23351201721 in words is "twenty-three billion, three hundred fifty-one million, two hundred one thousand, seven hundred twenty-one".