1312639 has 4 divisors (see below), whose sum is σ = 1320856. Its totient is φ = 1304424.

The previous prime is 1312637. The next prime is 1312657. The reversal of 1312639 is 9362131.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9362131 = 71 ⋅131861.

It is a cyclic number.

It is not a de Polignac number, because 1312639 - 2¹ = 1312637 is a prime.

It is a super-2 number, since 2×1312639² = 3446042288642, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1312637) 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, 3864 + ... + 4189.

It is an arithmetic number, because the mean of its divisors is an integer number (330214).

2^1312639 is an apocalyptic number.

1312639 is a deficient number, since it is larger than the sum of its proper divisors (8217).

1312639 is an equidigital number, since it uses as much as digits as its factorization.

1312639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8216.

The product of its digits is 972, while the sum is 25.

The square root of 1312639 is about 1145.7045867064. The cubic root of 1312639 is about 109.4918434602.

The spelling of 1312639 in words is "one million, three hundred twelve thousand, six hundred thirty-nine".