19981709672400 has 480 divisors, whose sum is σ = 81303367680000. Its totient is φ = 4565940364800.

The previous prime is 19981709672371. The next prime is 19981709672437. The reversal of 19981709672400 is 427690718991.

19981709672400 is a `hidden beast` number, since 1 + 9 + 9 + 8 + 1 + 70 + 96 + 72 + 400 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 277491601 + ... + 277563599.

It is an arithmetic number, because the mean of its divisors is an integer number (169382016000).

Almost surely, 2^{19981709672400} is an apocalyptic number.

19981709672400 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 19981709672400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40651683840000).

19981709672400 is an abundant number, since it is smaller than the sum of its proper divisors (61321658007600).

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

19981709672400 is a wasteful number, since it uses less digits than its factorization.

19981709672400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75704 (or 75687 counting only the distinct ones).

The product of its (nonzero) digits is 13716864, while the sum is 63.

The spelling of 19981709672400 in words is "nineteen trillion, nine hundred eighty-one billion, seven hundred nine million, six hundred seventy-two thousand, four hundred".