1311921 has 12 divisors (see below), whose sum is σ = 2040948. Its totient is φ = 807264.

The previous prime is 1311917. The next prime is 1311923. The reversal of 1311921 is 1291131.

It can be written as a sum of positive squares in 2 ways, for example, as 112896 + 1199025 = 336^2 + 1095^2 .

It is not a de Polignac number, because 1311921 - 2² = 1311917 is a prime.

It is a super-2 number, since 2×1311921² = 3442273420482, which contains 22 as substring.

It is a Smith number, since the sum of its digits (18) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 1311894 and 1311903.

It is not an unprimeable number, because it can be changed into a prime (1311923) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5490 + ... + 5723.

It is an arithmetic number, because the mean of its divisors is an integer number (170079).

2^1311921 is an apocalyptic number.

It is an amenable number.

1311921 is a deficient number, since it is larger than the sum of its proper divisors (729027).

1311921 is a wasteful number, since it uses less digits than its factorization.

1311921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11232 (or 11229 counting only the distinct ones).

The product of its digits is 54, while the sum is 18.

The square root of 1311921 is about 1145.3911995471. The cubic root of 1311921 is about 109.4718761826.

The spelling of 1311921 in words is "one million, three hundred eleven thousand, nine hundred twenty-one".