18219948720 has 80 divisors (see below), whose sum is σ = 56577530592. Its totient is φ = 4850421760.

The previous prime is 18219948707. The next prime is 18219948763. The reversal of 18219948720 is 2784991281.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

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, 78310 + ... + 206330.

Almost surely, 2^18219948720 is an apocalyptic number.

18219948720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18219948720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28288765296).

18219948720 is an abundant number, since it is smaller than the sum of its proper divisors (38357581872).

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

18219948720 is a wasteful number, since it uses less digits than its factorization.

18219948720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128630 (or 128624 counting only the distinct ones).

The product of its (nonzero) digits is 580608, while the sum is 51.

The spelling of 18219948720 in words is "eighteen billion, two hundred nineteen million, nine hundred forty-eight thousand, seven hundred twenty".