312155640 has 64 divisors (see below), whose sum is σ = 1040522400. Its totient is φ = 83241216.

The previous prime is 312155639. The next prime is 312155653. The reversal of 312155640 is 46551213.

312155640 is a `hidden beast` number, since 3 + 1 + 2 + 15 + 5 + 640 = 666.

It is a super-2 number, since 2×312155640² = 194882287167619200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 143437 + ... + 145596.

Almost surely, 2^312155640 is an apocalyptic number.

312155640 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

312155640 is an abundant number, since it is smaller than the sum of its proper divisors (728366760).

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

312155640 is a wasteful number, since it uses less digits than its factorization.

312155640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 289053 (or 289043 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The square root of 312155640 is about 17667.9268732922. The cubic root of 312155640 is about 678.3550493738.

The spelling of 312155640 in words is "three hundred twelve million, one hundred fifty-five thousand, six hundred forty".