13961377991 has 4 divisors (see below), whose sum is σ = 15230594184. Its totient is φ = 12692161800.

The previous prime is 13961377979. The next prime is 13961377999. The reversal of 13961377991 is 19977316931.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13961377991 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13961377999) 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, 634608080 + ... + 634608101.

It is an arithmetic number, because the mean of its divisors is an integer number (3807648546).

Almost surely, 2^13961377991 is an apocalyptic number.

13961377991 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

13961377991 is a deficient number, since it is larger than the sum of its proper divisors (1269216193).

13961377991 is a wasteful number, since it uses less digits than its factorization.

13961377991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1269216192.

The product of its digits is 1928934, while the sum is 56.

The spelling of 13961377991 in words is "thirteen billion, nine hundred sixty-one million, three hundred seventy-seven thousand, nine hundred ninety-one".