19921475660 has 48 divisors (see below), whose sum is σ = 42149854656. Its totient is φ = 7908755712.

The previous prime is 19921475617. The next prime is 19921475663. The reversal of 19921475660 is 6657412991.

It is a junction number, because it is equal to n+sod(n) for n = 19921475599 and 19921475608.

It is not an unprimeable number, because it can be changed into a prime (19921475663) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3177689 + ... + 3183951.

It is an arithmetic number, because the mean of its divisors is an integer number (878121972).

Almost surely, 2^19921475660 is an apocalyptic number.

19921475660 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19921475660 is an abundant number, since it is smaller than the sum of its proper divisors (22228378996).

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

19921475660 is a wasteful number, since it uses less digits than its factorization.

19921475660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7442 (or 7440 counting only the distinct ones).

The product of its (nonzero) digits is 816480, while the sum is 50.

The spelling of 19921475660 in words is "nineteen billion, nine hundred twenty-one million, four hundred seventy-five thousand, six hundred sixty".