1397891 has 4 divisors (see below), whose sum is σ = 1524984. Its totient is φ = 1270800.

The previous prime is 1397881. The next prime is 1397909. The reversal of 1397891 is 1987931.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1397891 - 2¹⁰ = 1396867 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1397861) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 63530 + ... + 63551.

It is an arithmetic number, because the mean of its divisors is an integer number (381246).

2^1397891 is an apocalyptic number.

1397891 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1397891 is a deficient number, since it is larger than the sum of its proper divisors (127093).

1397891 is a wasteful number, since it uses less digits than its factorization.

1397891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127092.

The product of its digits is 13608, while the sum is 38.

The square root of 1397891 is about 1182.3244055673. The cubic root of 1397891 is about 111.8126918109.

The spelling of 1397891 in words is "one million, three hundred ninety-seven thousand, eight hundred ninety-one".