2091721320 has 320 divisors, whose sum is σ = 7722403920. Its totient is φ = 504631296.

The previous prime is 2091721243. The next prime is 2091721321. The reversal of 2091721320 is 231271902.

It can be written as a sum of positive squares in 8 ways, for example, as 254913156 + 1836808164 = 15966^2 + 42858^2 .

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (2091721321) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 2231892 + ... + 2232828.

Almost surely, 2^2091721320 is an apocalyptic number.

2091721320 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 2091721320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3861201960).

2091721320 is an abundant number, since it is smaller than the sum of its proper divisors (5630682600).

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

2091721320 is a wasteful number, since it uses less digits than its factorization.

2091721320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1026 (or 1013 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 27.

The square root of 2091721320 is about 45735.3399462604. The cubic root of 2091721320 is about 1278.8941702417.

The spelling of 2091721320 in words is "two billion, ninety-one million, seven hundred twenty-one thousand, three hundred twenty".