19864655460 has 540 divisors, whose sum is σ = 70659995868. Its totient is φ = 4667839488.

The previous prime is 19864655453. The next prime is 19864655471. The reversal of 19864655460 is 6455646891.

19864655460 is a `hidden beast` number, since 1 + 9 + 86 + 4 + 6 + 554 + 6 + 0 = 666.

It can be written as a sum of positive squares in 18 ways, for example, as 7804662336 + 12059993124 = 88344^2 + 109818^2 .

It is a tau number, because it is divible by the number of its divisors (540).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a junction number, because it is equal to n+sod(n) for n = 19864655397 and 19864655406.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 179 ways as a sum of consecutive naturals, for example, 374804794 + ... + 374804846.

Almost surely, 2^19864655460 is an apocalyptic number.

19864655460 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19864655460, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35329997934).

19864655460 is an abundant number, since it is smaller than the sum of its proper divisors (50795340408).

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

19864655460 is a wasteful number, since it uses less digits than its factorization.

19864655460 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 174 (or 113 counting only the distinct ones).

The product of its (nonzero) digits is 6220800, while the sum is 54.

The spelling of 19864655460 in words is "nineteen billion, eight hundred sixty-four million, six hundred fifty-five thousand, four hundred sixty".