2191997280 has 384 divisors, whose sum is σ = 7862593536. Its totient is φ = 512962560.

The previous prime is 2191997261. The next prime is 2191997299. The reversal of 2191997280 is 827991912.

It is an interprime number because it is at equal distance from previous prime (2191997261) and next prime (2191997299).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 30027324 + ... + 30027396.

It is an arithmetic number, because the mean of its divisors is an integer number (20475504).

Almost surely, 2^2191997280 is an apocalyptic number.

2191997280 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 2191997280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3931296768).

2191997280 is an abundant number, since it is smaller than the sum of its proper divisors (5670596256).

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

2191997280 is a wasteful number, since it uses less digits than its factorization.

2191997280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 171 (or 141 counting only the distinct ones).

The product of its (nonzero) digits is 163296, while the sum is 48.

The square root of 2191997280 is about 46818.7705947091. The cubic root of 2191997280 is about 1299.0125203176.

The spelling of 2191997280 in words is "two billion, one hundred ninety-one million, nine hundred ninety-seven thousand, two hundred eighty".