2109786840 has 384 divisors, whose sum is σ = 8194867200. Its totient is φ = 460615680.

The previous prime is 2109786823. The next prime is 2109786851. The reversal of 2109786840 is 486879012.

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 95 ways as a sum of consecutive naturals, for example, 8827441 + ... + 8827679.

It is an arithmetic number, because the mean of its divisors is an integer number (21340800).

Almost surely, 2^2109786840 is an apocalyptic number.

2109786840 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 2109786840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4097433600).

2109786840 is an abundant number, since it is smaller than the sum of its proper divisors (6085080360).

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

2109786840 is a wasteful number, since it uses less digits than its factorization.

2109786840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 407 (or 400 counting only the distinct ones).

The product of its (nonzero) digits is 193536, while the sum is 45.

The square root of 2109786840 is about 45932.4160043863. The cubic root of 2109786840 is about 1282.5654196421.

The spelling of 2109786840 in words is "two billion, one hundred nine million, seven hundred eighty-six thousand, eight hundred forty".