23207640 has 128 divisors (see below), whose sum is σ = 73483200. Its totient is φ = 5857280.

The previous prime is 23207629. The next prime is 23207641. The reversal of 23207640 is 4670232.

23207640 = 466² + 467² + ... + 554².

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 23207640.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23207641) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 260716 + ... + 260804.

Almost surely, 2^23207640 is an apocalyptic number.

23207640 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 23207640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36741600).

23207640 is an abundant number, since it is smaller than the sum of its proper divisors (50275560).

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

23207640 is a wasteful number, since it uses less digits than its factorization.

23207640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 197 (or 193 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 24.

The square root of 23207640 is about 4817.4308505676. The cubic root of 23207640 is about 285.2399333765.

Adding to 23207640 its reverse (4670232), we get a palindrome (27877872).

The spelling of 23207640 in words is "twenty-three million, two hundred seven thousand, six hundred forty".