23997417921 has 9 divisors (see below), whose sum is σ = 34663608291. Its totient is φ = 15997968792.

The previous prime is 23997417907. The next prime is 23997418009. The reversal of 23997417921 is 12971479932.

It is a happy number.

The square root of 23997417921 is 154911.

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

It can be written as a sum of positive squares in only one way, i.e., 7655375025 + 16342042896 = 87495^2 + 127836^2 .

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 23997417921 - 2²⁵ = 23963863489 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (23997416921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 438915 + ... + 490551.

Almost surely, 2^23997417921 is an apocalyptic number.

23997417921 is the 154911-st square number.

23997417921 is the 77456-th centered octagonal number.

It is an amenable number.

23997417921 is a deficient number, since it is larger than the sum of its proper divisors (10666190370).

23997417921 is an frugal number, since it uses more digits than its factorization.

23997417921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103280 (or 51640 counting only the distinct ones).

The product of its digits is 1714608, while the sum is 54.

The spelling of 23997417921 in words is "twenty-three billion, nine hundred ninety-seven million, four hundred seventeen thousand, nine hundred twenty-one".