23121571 has 4 divisors (see below), whose sum is σ = 25223544. Its totient is φ = 21019600.

The previous prime is 23121557. The next prime is 23121583. The reversal of 23121571 is 17512132.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 23121571 - 2¹³ = 23113379 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (23121521) 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, 1050970 + ... + 1050991.

It is an arithmetic number, because the mean of its divisors is an integer number (6305886).

Almost surely, 2^23121571 is an apocalyptic number.

23121571 is a deficient number, since it is larger than the sum of its proper divisors (2101973).

23121571 is a wasteful number, since it uses less digits than its factorization.

23121571 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2101972.

The product of its digits is 420, while the sum is 22.

The square root of 23121571 is about 4808.4894717572. The cubic root of 23121571 is about 284.8868782617.

It can be divided in two parts, 23121 and 571, that multiplied together give a triangular number (13202091 = T₅₁₃₈).

The spelling of 23121571 in words is "twenty-three million, one hundred twenty-one thousand, five hundred seventy-one".