12641640 has 128 divisors (see below), whose sum is σ = 42318720. Its totient is φ = 2995200.

The previous prime is 12641639. The next prime is 12641641. The reversal of 12641640 is 4614621.

It is an interprime number because it is at equal distance from previous prime (12641639) and next prime (12641641).

It is a super-2 number, since 2×12641640² = 319622123779200, which contains 22 as substring.

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 12641640.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12641641) 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, 80442 + ... + 80598.

It is an arithmetic number, because the mean of its divisors is an integer number (330615).

Almost surely, 2^12641640 is an apocalyptic number.

12641640 is a gapful number since it is divisible by the number (10) 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 12641640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21159360).

12641640 is an abundant number, since it is smaller than the sum of its proper divisors (29677080).

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

12641640 is a wasteful number, since it uses less digits than its factorization.

12641640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 243 (or 239 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 12641640 is about 3555.5084024651. The cubic root of 12641640 is about 232.9527309909.

The spelling of 12641640 in words is "twelve million, six hundred forty-one thousand, six hundred forty".