312642640 has 40 divisors (see below), whose sum is σ = 734406120. Its totient is φ = 123764736.

The previous prime is 312642623. The next prime is 312642641. The reversal of 312642640 is 46246213.

It can be written as a sum of positive squares in 4 ways, for example, as 100881936 + 211760704 = 10044^2 + 14552^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 312642599 and 312642608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (312642641) 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, 12385 + ... + 27904.

It is an arithmetic number, because the mean of its divisors is an integer number (18360153).

Almost surely, 2^312642640 is an apocalyptic number.

It is an amenable number.

312642640 is an abundant number, since it is smaller than the sum of its proper divisors (421763480).

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

312642640 is a wasteful number, since it uses less digits than its factorization.

312642640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40399 (or 40393 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 28.

The square root of 312642640 is about 17681.7035378382. The cubic root of 312642640 is about 678.7076376511.

Adding to 312642640 its reverse (46246213), we get a palindrome (358888853).

The spelling of 312642640 in words is "three hundred twelve million, six hundred forty-two thousand, six hundred forty".