19981652745672 has 24 divisors (see below), whose sum is σ = 54116976186390. Its totient is φ = 6660550915200.

The previous prime is 19981652745671. The next prime is 19981652745787. The reversal of 19981652745672 is 27654725618991.

19981652745672 is a `hidden beast` number, since 1 + 9 + 9 + 8 + 1 + 6 + 52 + 7 + 4 + 567 + 2 = 666.

It can be written as a sum of positive squares in only one way, i.e., 19315022952996 + 666629792676 = 4394886^2 + 816474^2 .

It is a tau number, because it is divible by the number of its divisors (24).

It is a Harshad number since it is a multiple of its sum of digits (72), and also a Moran number because the ratio is a prime number: 277522954801 = 19981652745672 / (1 + 9 + 9 + 8 + 1 + 6 + 5 + 2 + 7 + 4 + 5 + 6 + 7 + 2).

It is a self number, because there is not a number n which added to its sum of digits gives 19981652745672.

It is not an unprimeable number, because it can be changed into a prime (19981652745671) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 138761477329 + ... + 138761477472.

Almost surely, 2^{19981652745672} is an apocalyptic number.

19981652745672 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

19981652745672 is an abundant number, since it is smaller than the sum of its proper divisors (34135323440718).

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

19981652745672 is a wasteful number, since it uses less digits than its factorization.

19981652745672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 277522954813 (or 277522954806 counting only the distinct ones).

The product of its digits is 457228800, while the sum is 72.

The spelling of 19981652745672 in words is "nineteen trillion, nine hundred eighty-one billion, six hundred fifty-two million, seven hundred forty-five thousand, six hundred seventy-two".