13961780639 has 4 divisors (see below), whose sum is σ = 14286473256. Its totient is φ = 13637088024.

The previous prime is 13961780627. The next prime is 13961780641. The reversal of 13961780639 is 93608716931.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 93608716931 = 1279 ⋅73188989.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13961780639 is a prime.

It is a super-2 number, since 2×13961780639² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13961780669) 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, 162346244 + ... + 162346329.

It is an arithmetic number, because the mean of its divisors is an integer number (3571618314).

Almost surely, 2^13961780639 is an apocalyptic number.

13961780639 is a deficient number, since it is larger than the sum of its proper divisors (324692617).

13961780639 is an equidigital number, since it uses as much as digits as its factorization.

13961780639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 324692616.

The product of its (nonzero) digits is 1469664, while the sum is 53.

The spelling of 13961780639 in words is "thirteen billion, nine hundred sixty-one million, seven hundred eighty thousand, six hundred thirty-nine".