1377939691 has 2 divisors, whose sum is σ = 1377939692. Its totient is φ = 1377939690.

The previous prime is 1377939643. The next prime is 1377939701. The reversal of 1377939691 is 1969397731.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1377939691 - 2²³ = 1369551083 is a prime.

It is not a weakly prime, because it can be changed into another prime (1377939791) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 688969845 + 688969846.

It is an arithmetic number, because the mean of its divisors is an integer number (688969846).

Almost surely, 2^1377939691 is an apocalyptic number.

1377939691 is a deficient number, since it is larger than the sum of its proper divisors (1).

1377939691 is an equidigital number, since it uses as much as digits as its factorization.

1377939691 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1928934, while the sum is 55.

The square root of 1377939691 is about 37120.6100569481. The cubic root of 1377939691 is about 1112.7819435384.

It can be divided in two parts, 1377939 and 691, that added together give a triangular number (1378630 = T₁₆₆₀).

The spelling of 1377939691 in words is "one billion, three hundred seventy-seven million, nine hundred thirty-nine thousand, six hundred ninety-one".