1391696641 has 4 divisors (see below), whose sum is σ = 1392669252. Its totient is φ = 1390724032.

The previous prime is 1391696633. The next prime is 1391696711. The reversal of 1391696641 is 1466961931.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1466961931 = 53 ⋅27678527.

It can be written as a sum of positive squares in 2 ways, for example, as 615238416 + 776458225 = 24804^2 + 27865^2 .

It is a cyclic number.

It is not a de Polignac number, because 1391696641 - 2³ = 1391696633 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1391696591 and 1391696600.

It is not an unprimeable number, because it can be changed into a prime (1391696611) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 484156 + ... + 487021.

It is an arithmetic number, because the mean of its divisors is an integer number (348167313).

Almost surely, 2^1391696641 is an apocalyptic number.

It is an amenable number.

1391696641 is a deficient number, since it is larger than the sum of its proper divisors (972611).

1391696641 is an equidigital number, since it uses as much as digits as its factorization.

1391696641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 972610.

The product of its digits is 209952, while the sum is 46.

The square root of 1391696641 is about 37305.4505535049. The cubic root of 1391696641 is about 1116.4729181143.

The spelling of 1391696641 in words is "one billion, three hundred ninety-one million, six hundred ninety-six thousand, six hundred forty-one".