1313991 has 12 divisors (see below), whose sum is σ = 2169232. Its totient is φ = 750816.

The previous prime is 1313987. The next prime is 1313999. The reversal of 1313991 is 1993131.

It is not a de Polignac number, because 1313991 - 2² = 1313987 is a prime.

It is a nude number because it is divisible by every one of its digits.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1313999) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10366 + ... + 10491.

2^1313991 is an apocalyptic number.

1313991 is a deficient number, since it is larger than the sum of its proper divisors (855241).

1313991 is a wasteful number, since it uses less digits than its factorization.

1313991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20870 (or 20867 counting only the distinct ones).

The product of its digits is 729, while the sum is 27.

The square root of 1313991 is about 1146.2944647864. The cubic root of 1313991 is about 109.5294222556.

It can be divided in two parts, 1313 and 991, that added together give a square (2304 = 48²).

The spelling of 1313991 in words is "one million, three hundred thirteen thousand, nine hundred ninety-one".