1380831691 has 2 divisors, whose sum is σ = 1380831692. Its totient is φ = 1380831690.

The previous prime is 1380831689. The next prime is 1380831721. The reversal of 1380831691 is 1961380831.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1380831691 - 2¹ = 1380831689 is a prime.

Together with 1380831689, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1380831391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 690415845 + 690415846.

It is an arithmetic number, because the mean of its divisors is an integer number (690415846).

Almost surely, 2^1380831691 is an apocalyptic number.

1380831691 is a deficient number, since it is larger than the sum of its proper divisors (1).

1380831691 is an equidigital number, since it uses as much as digits as its factorization.

1380831691 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 31104, while the sum is 40.

The square root of 1380831691 is about 37159.5437404713. The cubic root of 1380831691 is about 1113.5598964513.

The spelling of 1380831691 in words is "one billion, three hundred eighty million, eight hundred thirty-one thousand, six hundred ninety-one".