12778040691 has 48 divisors (see below), whose sum is σ = 20995566592. Its totient is φ = 7432689600.

The previous prime is 12778040659. The next prime is 12778040731. The reversal of 12778040691 is 19604087721.

It is a happy number.

12778040691 is a `hidden beast` number, since 12 + 77 + 80 + 406 + 91 = 666.

It is not a de Polignac number, because 12778040691 - 2⁵ = 12778040659 is a prime.

It is not an unprimeable number, because it can be changed into a prime (12778040491) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 114996 + ... + 196926.

Almost surely, 2^12778040691 is an apocalyptic number.

12778040691 is a deficient number, since it is larger than the sum of its proper divisors (8217525901).

12778040691 is a wasteful number, since it uses less digits than its factorization.

12778040691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82024 (or 82021 counting only the distinct ones).

The product of its (nonzero) digits is 169344, while the sum is 45.

The spelling of 12778040691 in words is "twelve billion, seven hundred seventy-eight million, forty thousand, six hundred ninety-one".