1320891 has 16 divisors (see below), whose sum is σ = 2069760. Its totient is φ = 738720.

The previous prime is 1320889. The next prime is 1320901. The reversal of 1320891 is 1980231.

1320891 = T₅₈ + T₅₉ + ... + T₂₀₀.

It is not a de Polignac number, because 1320891 - 2¹ = 1320889 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1320811) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1111 + ... + 1968.

It is an arithmetic number, because the mean of its divisors is an integer number (129360).

2^1320891 is an apocalyptic number.

1320891 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1320891 is a deficient number, since it is larger than the sum of its proper divisors (748869).

1320891 is a wasteful number, since it uses less digits than its factorization.

1320891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3106.

The product of its (nonzero) digits is 432, while the sum is 24.

The square root of 1320891 is about 1149.3002218742. The cubic root of 1320891 is about 109.7208071269.

It can be divided in two parts, 1320 and 891, that added together give a triangular number (2211 = T₆₆).

The spelling of 1320891 in words is "one million, three hundred twenty thousand, eight hundred ninety-one".