19781536704 has 56 divisors (see below), whose sum is σ = 52557761280. Its totient is φ = 6566241024.

The previous prime is 19781536681. The next prime is 19781536727. The reversal of 19781536704 is 40763518791.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (19781536681) and next prime (19781536727).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 169654 + ... + 261429.

Almost surely, 2^19781536704 is an apocalyptic number.

It is an amenable number.

19781536704 is an abundant number, since it is smaller than the sum of its proper divisors (32776224576).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

19781536704 is a wasteful number, since it uses less digits than its factorization.

19781536704 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 431337 (or 431327 counting only the distinct ones).

The product of its (nonzero) digits is 1270080, while the sum is 51.

The spelling of 19781536704 in words is "nineteen billion, seven hundred eighty-one million, five hundred thirty-six thousand, seven hundred four".