2191955220 has 288 divisors, whose sum is σ = 8353363200. Its totient is φ = 462309120.

The previous prime is 2191955219. The next prime is 2191955261. The reversal of 2191955220 is 225591912.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 801255 + ... + 803985.

Almost surely, 2^2191955220 is an apocalyptic number.

2191955220 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 2191955220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4176681600).

2191955220 is an abundant number, since it is smaller than the sum of its proper divisors (6161407980).

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

2191955220 is a wasteful number, since it uses less digits than its factorization.

2191955220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2780 (or 2761 counting only the distinct ones).

The product of its (nonzero) digits is 16200, while the sum is 36.

The square root of 2191955220 is about 46818.3214137372. The cubic root of 2191955220 is about 1299.0042117890.

The spelling of 2191955220 in words is "two billion, one hundred ninety-one million, nine hundred fifty-five thousand, two hundred twenty".