1389438931 has 2 divisors, whose sum is σ = 1389438932. Its totient is φ = 1389438930.

The previous prime is 1389438913. The next prime is 1389438943. The reversal of 1389438931 is 1398349831.

Together with previous prime (1389438913) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1389438931 - 2¹⁹ = 1388914643 is a prime.

It is a super-2 number, since 2×1389438931² = 3861081085956845522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1389438971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 694719465 + 694719466.

It is an arithmetic number, because the mean of its divisors is an integer number (694719466).

Almost surely, 2^1389438931 is an apocalyptic number.

1389438931 is a deficient number, since it is larger than the sum of its proper divisors (1).

1389438931 is an equidigital number, since it uses as much as digits as its factorization.

1389438931 is an evil number, because the sum of its binary digits is even.

The product of its digits is 559872, while the sum is 49.

The square root of 1389438931 is about 37275.1784838114. The cubic root of 1389438931 is about 1115.8688505565.

It can be divided in two parts, 13894 and 38931, that added together give a palindrome (52825).

The spelling of 1389438931 in words is "one billion, three hundred eighty-nine million, four hundred thirty-eight thousand, nine hundred thirty-one".