1313981 has 8 divisors (see below), whose sum is σ = 1429560. Its totient is φ = 1202688.

The previous prime is 1313959. The next prime is 1313987. The reversal of 1313981 is 1893131.

It can be written as a sum of positive squares in 4 ways, for example, as 912025 + 401956 = 955^2 + 634^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1313981 is a prime.

It is a super-2 number, since 2×1313981² = 3453092136722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1313981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1313987) 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, 416 + ... + 1673.

It is an arithmetic number, because the mean of its divisors is an integer number (178695).

2^1313981 is an apocalyptic number.

It is an amenable number.

1313981 is a deficient number, since it is larger than the sum of its proper divisors (115579).

1313981 is a wasteful number, since it uses less digits than its factorization.

1313981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2143.

The product of its digits is 648, while the sum is 26.

The square root of 1313981 is about 1146.2901028972. The cubic root of 1313981 is about 109.5291444006.

The spelling of 1313981 in words is "one million, three hundred thirteen thousand, nine hundred eighty-one".