1397661 has 4 divisors (see below), whose sum is σ = 1863552. Its totient is φ = 931772.

The previous prime is 1397657. The next prime is 1397681. The reversal of 1397661 is 1667931.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1397661 - 2² = 1397657 is a prime.

It is a D-number.

It is a Curzon number.

1397661 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1397681) 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, 232941 + ... + 232946.

It is an arithmetic number, because the mean of its divisors is an integer number (465888).

2^1397661 is an apocalyptic number.

It is an amenable number.

1397661 is a deficient number, since it is larger than the sum of its proper divisors (465891).

1397661 is an equidigital number, since it uses as much as digits as its factorization.

1397661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 465890.

The product of its digits is 6804, while the sum is 33.

The square root of 1397661 is about 1182.2271355370. The cubic root of 1397661 is about 111.8065591607.

The spelling of 1397661 in words is "one million, three hundred ninety-seven thousand, six hundred sixty-one".