16620781171720 has 64 divisors (see below), whose sum is σ = 42570222157440. Its totient is φ = 5781141273600.

The previous prime is 16620781171711. The next prime is 16620781171783. The reversal of 16620781171720 is 2717118702661.

16620781171720 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×16620781171720² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 821174721 + ... + 821194960.

It is an arithmetic number, because the mean of its divisors is an integer number (665159721210).

Almost surely, 2^{16620781171720} is an apocalyptic number.

16620781171720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

16620781171720 is an abundant number, since it is smaller than the sum of its proper divisors (25949440985720).

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

16620781171720 is a wasteful number, since it uses less digits than its factorization.

16620781171720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1642369726 (or 1642369722 counting only the distinct ones).

The product of its (nonzero) digits is 395136, while the sum is 49.

The spelling of 16620781171720 in words is "sixteen trillion, six hundred twenty billion, seven hundred eighty-one million, one hundred seventy-one thousand, seven hundred twenty".