12636432640 has 72 divisors (see below), whose sum is σ = 32596571448. Its totient is φ = 4665753600.

The previous prime is 12636432631. The next prime is 12636432649. The reversal of 12636432640 is 4623463621.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (12636432631) and next prime (12636432649).

It can be written as a sum of positive squares in 4 ways, for example, as 63744256 + 12572688384 = 7984^2 + 112128^2 .

It is a super-3 number, since 3×12636432640³ (a number of 31 digits) contains 333 as substring.

It is a hoax number, since the sum of its digits (37) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 12636432640.

It is not an unprimeable number, because it can be changed into a prime (12636432649) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 363061 + ... + 396340.

It is an arithmetic number, because the mean of its divisors is an integer number (452730159).

Almost surely, 2^12636432640 is an apocalyptic number.

12636432640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12636432640 is an abundant number, since it is smaller than the sum of its proper divisors (19960138808).

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

12636432640 is an equidigital number, since it uses as much as digits as its factorization.

12636432640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 759435 (or 759421 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 37.

The spelling of 12636432640 in words is "twelve billion, six hundred thirty-six million, four hundred thirty-two thousand, six hundred forty".