19461731328 has 220 divisors, whose sum is σ = 62590504900. Its totient is φ = 5987893248.

The previous prime is 19461731297. The next prime is 19461731347. The reversal of 19461731328 is 82313716491.

19461731328 is a `hidden beast` number, since 1 + 9 + 4 + 617 + 3 + 1 + 3 + 28 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 9929723904 + 9532007424 = 99648^2 + 97632^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1069248 + ... + 1087296.

It is an arithmetic number, because the mean of its divisors is an integer number (284502295).

Almost surely, 2^19461731328 is an apocalyptic number.

19461731328 is a gapful number since it is divisible by the number (18) 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 19461731328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31295252450).

19461731328 is an abundant number, since it is smaller than the sum of its proper divisors (43128773572).

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

19461731328 is a wasteful number, since it uses less digits than its factorization.

19461731328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18094 (or 18067 counting only the distinct ones).

The product of its digits is 217728, while the sum is 45.

The spelling of 19461731328 in words is "nineteen billion, four hundred sixty-one million, seven hundred thirty-one thousand, three hundred twenty-eight".