19973977937992 has 96 divisors (see below), whose sum is σ = 41596169193000. Its totient is φ = 8984111904768.

The previous prime is 19973977937983. The next prime is 19973977938119. The reversal of 19973977937992 is 29973977937991.

It can be written as a sum of positive squares in 12 ways, for example, as 706215013956 + 19267762924036 = 840366^2 + 4389506^2 .

It is a super-2 number, since 2×19973977937992² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 19973977937897 and 19973977937906.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9741348 + ... + 11612140.

Almost surely, 2^{19973977937992} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19973977937992, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20798084596500).

19973977937992 is an abundant number, since it is smaller than the sum of its proper divisors (21622191255008).

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

19973977937992 is a wasteful number, since it uses less digits than its factorization.

19973977937992 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1871027 (or 1871010 counting only the distinct ones).

The product of its digits is 22967817138, while the sum is 91.

Subtracting 19973977937992 from its reverse (29973977937991), we obtain a palindrome (9999999999999).

The spelling of 19973977937992 in words is "nineteen trillion, nine hundred seventy-three billion, nine hundred seventy-seven million, nine hundred thirty-seven thousand, nine hundred ninety-two".