1399139431 has 2 divisors, whose sum is σ = 1399139432. Its totient is φ = 1399139430.

The previous prime is 1399139377. The next prime is 1399139437. The reversal of 1399139431 is 1349319931.

It is a strong prime.

It is an emirp because it is prime and its reverse (1349319931) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1399139431 is a prime.

It is a super-2 number, since 2×1399139431² = 3915182294758007522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1399139437) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 699569715 + 699569716.

It is an arithmetic number, because the mean of its divisors is an integer number (699569716).

Almost surely, 2^1399139431 is an apocalyptic number.

1399139431 is a deficient number, since it is larger than the sum of its proper divisors (1).

1399139431 is an equidigital number, since it uses as much as digits as its factorization.

1399139431 is an evil number, because the sum of its binary digits is even.

The product of its digits is 78732, while the sum is 43.

The square root of 1399139431 is about 37405.0722629966. The cubic root of 1399139431 is about 1118.4596786652.

The spelling of 1399139431 in words is "one billion, three hundred ninety-nine million, one hundred thirty-nine thousand, four hundred thirty-one".