2171988720 has 360 divisors, whose sum is σ = 8127323568. Its totient is φ = 519383040.

The previous prime is 2171988719. The next prime is 2171988733. The reversal of 2171988720 is 278891712.

2171988720 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (360).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 9321724 + ... + 9321956.

Almost surely, 2^2171988720 is an apocalyptic number.

2171988720 is a gapful number since it is divisible by the number (20) 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 2171988720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4063661784).

2171988720 is an abundant number, since it is smaller than the sum of its proper divisors (5955334848).

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

2171988720 is a wasteful number, since it uses less digits than its factorization.

2171988720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 381 (or 361 counting only the distinct ones).

The product of its (nonzero) digits is 112896, while the sum is 45.

The square root of 2171988720 is about 46604.5997729838. The cubic root of 2171988720 is about 1295.0479690842.

The spelling of 2171988720 in words is "two billion, one hundred seventy-one million, nine hundred eighty-eight thousand, seven hundred twenty".