23281664 has 90 divisors (see below), whose sum is σ = 56031570. Its totient is φ = 9633792.

The previous prime is 23281663. The next prime is 23281673. The reversal of 23281664 is 46618232.

It can be written as a sum of positive squares in only one way, i.e., 20070400 + 3211264 = 4480^2 + 1792^2 .

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a self number, because there is not a number n which added to its sum of digits gives 23281664.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23281663) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 802802 + ... + 802830.

It is an arithmetic number, because the mean of its divisors is an integer number (622573).

Almost surely, 2^23281664 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 23281664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28015785).

23281664 is an abundant number, since it is smaller than the sum of its proper divisors (32749906).

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

23281664 is an frugal number, since it uses more digits than its factorization.

23281664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71 (or 38 counting only the distinct ones).

The product of its digits is 13824, while the sum is 32.

The square root of 23281664 is about 4825.1076671925. The cubic root of 23281664 is about 285.5428823365.

Adding to 23281664 its reverse (46618232), we get a palindrome (69899896).

The spelling of 23281664 in words is "twenty-three million, two hundred eighty-one thousand, six hundred sixty-four".