1312403240 has 16 divisors (see below), whose sum is σ = 2952907380. Its totient is φ = 524961280.

The previous prime is 1312403201. The next prime is 1312403243. The reversal of 1312403240 is 423042131.

It can be written as a sum of positive squares in 2 ways, for example, as 1273490596 + 38912644 = 35686^2 + 6238^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is not an unprimeable number, because it can be changed into a prime (1312403243) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16405001 + ... + 16405080.

Almost surely, 2^1312403240 is an apocalyptic number.

1312403240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1312403240 is an abundant number, since it is smaller than the sum of its proper divisors (1640504140).

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

1312403240 is a wasteful number, since it uses less digits than its factorization.

1312403240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32810092 (or 32810088 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

The square root of 1312403240 is about 36227.1064259899. The cubic root of 1312403240 is about 1094.8528787697.

Adding to 1312403240 its reverse (423042131), we get a palindrome (1735445371).

The spelling of 1312403240 in words is "one billion, three hundred twelve million, four hundred three thousand, two hundred forty".