1399631 has 4 divisors (see below), whose sum is σ = 1405872. Its totient is φ = 1393392.

The previous prime is 1399621. The next prime is 1399633. The reversal of 1399631 is 1369931.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1399631 is a prime.

It is a super-2 number, since 2×1399631² = 3917933872322, which contains 22 as substring.

It is a Duffinian number.

It is a nialpdrome in base 11.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1399633) 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 3 ways as a sum of consecutive naturals, for example, 2771 + ... + 3236.

It is an arithmetic number, because the mean of its divisors is an integer number (351468).

2^1399631 is an apocalyptic number.

1399631 is a deficient number, since it is larger than the sum of its proper divisors (6241).

1399631 is an equidigital number, since it uses as much as digits as its factorization.

1399631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6240.

The product of its digits is 4374, while the sum is 32.

The square root of 1399631 is about 1183.0600153838. The cubic root of 1399631 is about 111.8590648631.

The spelling of 1399631 in words is "one million, three hundred ninety-nine thousand, six hundred thirty-one".