19966668725520 has 360 divisors, whose sum is σ = 76082368916736. Its totient is φ = 4684261824000.

The previous prime is 19966668725519. The next prime is 19966668725539. The reversal of 19966668725520 is 2552786666991.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (360).

It is a super-2 number, since 2×19966668725520² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 995826 + ... + 6397265.

Almost surely, 2^{19966668725520} is an apocalyptic number.

19966668725520 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 19966668725520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38041184458368).

19966668725520 is an abundant number, since it is smaller than the sum of its proper divisors (56115700191216).

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

19966668725520 is a wasteful number, since it uses less digits than its factorization.

19966668725520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7393163 (or 7393143 counting only the distinct ones).

The product of its (nonzero) digits is 587865600, while the sum is 72.

The spelling of 19966668725520 in words is "nineteen trillion, nine hundred sixty-six billion, six hundred sixty-eight million, seven hundred twenty-five thousand, five hundred twenty".