1340991 has 12 divisors (see below), whose sum is σ = 1989832. Its totient is φ = 869616.

The previous prime is 1340981. The next prime is 1341007. The reversal of 1340991 is 1990431.

It is not a de Polignac number, because 1340991 - 2⁵ = 1340959 is a prime.

It is a Duffinian number.

1340991 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1340981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1681 + ... + 2346.

2^1340991 is an apocalyptic number.

1340991 is a deficient number, since it is larger than the sum of its proper divisors (648841).

1340991 is a wasteful number, since it uses less digits than its factorization.

1340991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4070 (or 4067 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 27.

The square root of 1340991 is about 1158.0116579724. The cubic root of 1340991 is about 110.2745483461.

Subtracting from 1340991 its sum of digits (27), we obtain a square (1340964 = 1158²).

The spelling of 1340991 in words is "one million, three hundred forty thousand, nine hundred ninety-one".