1387311791 has 2 divisors, whose sum is σ = 1387311792. Its totient is φ = 1387311790.

The previous prime is 1387311719. The next prime is 1387311823. The reversal of 1387311791 is 1971137831.

Together with previous prime (1387311719) 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 1387311791 - 2¹⁴ = 1387295407 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1387317791) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 693655895 + 693655896.

It is an arithmetic number, because the mean of its divisors is an integer number (693655896).

Almost surely, 2^1387311791 is an apocalyptic number.

1387311791 is a deficient number, since it is larger than the sum of its proper divisors (1).

1387311791 is an equidigital number, since it uses as much as digits as its factorization.

1387311791 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31752, while the sum is 41.

The square root of 1387311791 is about 37246.6346265002. The cubic root of 1387311791 is about 1115.2991190087.

The spelling of 1387311791 in words is "one billion, three hundred eighty-seven million, three hundred eleven thousand, seven hundred ninety-one".