19747427720 has 16 divisors (see below), whose sum is σ = 44431712460. Its totient is φ = 7898971072.

The previous prime is 19747427701. The next prime is 19747427723. The reversal of 19747427720 is 2772474791.

It can be written as a sum of positive squares in 2 ways, for example, as 18040250596 + 1707177124 = 134314^2 + 41318^2 .

It is not an unprimeable number, because it can be changed into a prime (19747427723) 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, 246842807 + ... + 246842886.

Almost surely, 2^19747427720 is an apocalyptic number.

19747427720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19747427720 is an abundant number, since it is smaller than the sum of its proper divisors (24684284740).

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

19747427720 is a wasteful number, since it uses less digits than its factorization.

19747427720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 493685704 (or 493685700 counting only the distinct ones).

The product of its (nonzero) digits is 1382976, while the sum is 50.

The spelling of 19747427720 in words is "nineteen billion, seven hundred forty-seven million, four hundred twenty-seven thousand, seven hundred twenty".