2105616780 has 144 divisors (see below), whose sum is σ = 6525792000. Its totient is φ = 549394560.

The previous prime is 2105616767. The next prime is 2105616781. The reversal of 2105616780 is 876165012.

2105616780 is a `hidden beast` number, since 2 + 10 + 561 + 6 + 7 + 80 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (2105616781) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3514921 + ... + 3515519.

It is an arithmetic number, because the mean of its divisors is an integer number (45318000).

Almost surely, 2^2105616780 is an apocalyptic number.

2105616780 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 2105616780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3262896000).

2105616780 is an abundant number, since it is smaller than the sum of its proper divisors (4420175220).

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

2105616780 is a wasteful number, since it uses less digits than its factorization.

2105616780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1004 (or 999 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The square root of 2105616780 is about 45887.0001198597. Note that the first 3 decimals coincide. The cubic root of 2105616780 is about 1281.7198520125.

The spelling of 2105616780 in words is "two billion, one hundred five million, six hundred sixteen thousand, seven hundred eighty".