1312991040 has 112 divisors (see below), whose sum is σ = 4186123200. Its totient is φ = 348672000.

The previous prime is 1312991033. The next prime is 1312991047. The reversal of 1312991040 is 401992131.

It is an interprime number because it is at equal distance from previous prime (1312991033) and next prime (1312991047).

It is a super-2 number, since 2×1312991040² = 3447890942240563200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 1312990989 and 1312991007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1312991047) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 238236 + ... + 243684.

It is an arithmetic number, because the mean of its divisors is an integer number (37376100).

Almost surely, 2^1312991040 is an apocalyptic number.

1312991040 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 1312991040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2093061600).

1312991040 is an abundant number, since it is smaller than the sum of its proper divisors (2873132160).

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

1312991040 is a wasteful number, since it uses less digits than its factorization.

1312991040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5720 (or 5710 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 30.

The square root of 1312991040 is about 36235.2182275752. The cubic root of 1312991040 is about 1095.0163088416.

The spelling of 1312991040 in words is "one billion, three hundred twelve million, nine hundred ninety-one thousand, forty".