1396639 has 4 divisors (see below), whose sum is σ = 1434424. Its totient is φ = 1358856.

The previous prime is 1396627. The next prime is 1396657. The reversal of 1396639 is 9366931.

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 1396639 - 2⁵ = 1396607 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (37), and also a Moran number because the ratio is a prime number: 37747 = 1396639 / (1 + 3 + 9 + 6 + 6 + 3 + 9).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1396598 and 1396607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1396679) 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, 18837 + ... + 18910.

It is an arithmetic number, because the mean of its divisors is an integer number (358606).

2^1396639 is an apocalyptic number.

1396639 is a deficient number, since it is larger than the sum of its proper divisors (37785).

1396639 is an equidigital number, since it uses as much as digits as its factorization.

1396639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37784.

The product of its digits is 26244, while the sum is 37.

The square root of 1396639 is about 1181.7948214474. The cubic root of 1396639 is about 111.7793007229.

The spelling of 1396639 in words is "one million, three hundred ninety-six thousand, six hundred thirty-nine".