1387431 has 6 divisors (see below), whose sum is σ = 2004080. Its totient is φ = 924948.

The previous prime is 1387427. The next prime is 1387433. The reversal of 1387431 is 1347831.

It is not a de Polignac number, because 1387431 - 2² = 1387427 is a prime.

It is a super-2 number, since 2×1387431² = 3849929559522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1387395 and 1387404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1387433) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 77071 + ... + 77088.

2^1387431 is an apocalyptic number.

1387431 is a deficient number, since it is larger than the sum of its proper divisors (616649).

1387431 is a wasteful number, since it uses less digits than its factorization.

1387431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 154165 (or 154162 counting only the distinct ones).

The product of its digits is 2016, while the sum is 27.

The square root of 1387431 is about 1177.8926097060. The cubic root of 1387431 is about 111.5331063254.

It can be divided in two parts, 138 and 7431, that added together give a square (7569 = 87²).

The spelling of 1387431 in words is "one million, three hundred eighty-seven thousand, four hundred thirty-one".