19660838400 has 1260 divisors, whose sum is σ = 86933070972. Its totient is φ = 4389396480.

The previous prime is 19660838303. The next prime is 19660838401. The reversal of 19660838400 is 483806691.

19660838400 is a `hidden beast` number, since 1 + 9 + 6 + 608 + 38 + 4 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1260).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19660838401) by changing a digit.

It is a polite number, since it can be written in 125 ways as a sum of consecutive naturals, for example, 457228779 + ... + 457228821.

Almost surely, 2^19660838400 is an apocalyptic number.

19660838400 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 19660838400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43466535486).

19660838400 is an abundant number, since it is smaller than the sum of its proper divisors (67272232572).

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

19660838400 is an frugal number, since it uses more digits than its factorization.

19660838400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103 (or 60 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 45.

The spelling of 19660838400 in words is "nineteen billion, six hundred sixty million, eight hundred thirty-eight thousand, four hundred".