19391661860 has 24 divisors (see below), whose sum is σ = 40741270080. Its totient is φ = 7753087584.

The previous prime is 19391661841. The next prime is 19391661907. The reversal of 19391661860 is 6816619391.

It is a junction number, because it is equal to n+sod(n) for n = 19391661799 and 19391661808.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 178904 + ... + 266063.

It is an arithmetic number, because the mean of its divisors is an integer number (1697552920).

Almost surely, 2^19391661860 is an apocalyptic number.

19391661860 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19391661860 is an abundant number, since it is smaller than the sum of its proper divisors (21349608220).

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

19391661860 is a wasteful number, since it uses less digits than its factorization.

19391661860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 447155 (or 447153 counting only the distinct ones).

The product of its (nonzero) digits is 419904, while the sum is 50.

The spelling of 19391661860 in words is "nineteen billion, three hundred ninety-one million, six hundred sixty-one thousand, eight hundred sixty".