23121660 has 72 divisors (see below), whose sum is σ = 67063248. Its totient is φ = 5952000.

The previous prime is 23121643. The next prime is 23121661. The reversal of 23121660 is 6612132.

It is a happy number.

It is a super-2 number, since 2×23121660² = 1069222322311200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23121661) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 57460 + ... + 57860.

It is an arithmetic number, because the mean of its divisors is an integer number (931434).

Almost surely, 2^23121660 is an apocalyptic number.

23121660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 23121660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33531624).

23121660 is an abundant number, since it is smaller than the sum of its proper divisors (43941588).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

23121660 is a wasteful number, since it uses less digits than its factorization.

23121660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 475 (or 442 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 21.

The square root of 23121660 is about 4808.4987262138. The cubic root of 23121660 is about 284.8872437919.

Adding to 23121660 its reverse (6612132), we get a palindrome (29733792).

The spelling of 23121660 in words is "twenty-three million, one hundred twenty-one thousand, six hundred sixty".