19721868030 has 48 divisors (see below), whose sum is σ = 51330885840. Its totient is φ = 5253623424.

The previous prime is 19721867981. The next prime is 19721868031. The reversal of 19721868030 is 3086812791.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19721868031) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 29200 + ... + 200739.

It is an arithmetic number, because the mean of its divisors is an integer number (1069393455).

Almost surely, 2^19721868030 is an apocalyptic number.

19721868030 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

19721868030 is an abundant number, since it is smaller than the sum of its proper divisors (31609017810).

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

19721868030 is a wasteful number, since it uses less digits than its factorization.

19721868030 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 230905 (or 230902 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 45.

The spelling of 19721868030 in words is "nineteen billion, seven hundred twenty-one million, eight hundred sixty-eight thousand, thirty".