1312262640 has 320 divisors, whose sum is σ = 5155920000. Its totient is φ = 303906816.

The previous prime is 1312262639. The next prime is 1312262681. The reversal of 1312262640 is 462622131.

1312262640 is a `hidden beast` number, since 1 + 3 + 12 + 2 + 6 + 2 + 640 = 666.

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 63 ways as a sum of consecutive naturals, for example, 475986 + ... + 478734.

It is an arithmetic number, because the mean of its divisors is an integer number (16112250).

Almost surely, 2^1312262640 is an apocalyptic number.

1312262640 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 1312262640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2577960000).

1312262640 is an abundant number, since it is smaller than the sum of its proper divisors (3843657360).

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

1312262640 is a wasteful number, since it uses less digits than its factorization.

1312262640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2801 (or 2789 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 1312262640 is about 36225.1658381297. The cubic root of 1312262640 is about 1094.8137795540.

Adding to 1312262640 its reverse (462622131), we get a palindrome (1774884771).

The spelling of 1312262640 in words is "one billion, three hundred twelve million, two hundred sixty-two thousand, six hundred forty".