19681240636 has 24 divisors (see below), whose sum is σ = 34867322000. Its totient is φ = 9719557632.

The previous prime is 19681240627. The next prime is 19681240637. The reversal of 19681240636 is 63604218691.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19681240637) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 142786 + ... + 244438.

Almost surely, 2^19681240636 is an apocalyptic number.

It is an amenable number.

19681240636 is a deficient number, since it is larger than the sum of its proper divisors (15186081364).

19681240636 is a wasteful number, since it uses less digits than its factorization.

19681240636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102253 (or 102251 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 46.

The spelling of 19681240636 in words is "nineteen billion, six hundred eighty-one million, two hundred forty thousand, six hundred thirty-six".