2856661780 has 240 divisors, whose sum is σ = 7679669760. Its totient is φ = 889056000.

The previous prime is 2856661771. The next prime is 2856661789. The reversal of 2856661780 is 871666582.

It is an interprime number because it is at equal distance from previous prime (2856661771) and next prime (2856661789).

It is a Harshad number since it is a multiple of its sum of digits (49).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2856661789) by changing a digit.

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 79 ways as a sum of consecutive naturals, for example, 28283730 + ... + 28283830.

It is an arithmetic number, because the mean of its divisors is an integer number (31998624).

Almost surely, 2^2856661780 is an apocalyptic number.

2856661780 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 2856661780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3839834880).

2856661780 is an abundant number, since it is smaller than the sum of its proper divisors (4823007980).

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

2856661780 is a wasteful number, since it uses less digits than its factorization.

2856661780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 188 (or 165 counting only the distinct ones).

The product of its (nonzero) digits is 967680, while the sum is 49.

The square root of 2856661780 is about 53447.7481284291. The cubic root of 2856661780 is about 1418.9037661101.

The spelling of 2856661780 in words is "two billion, eight hundred fifty-six million, six hundred sixty-one thousand, seven hundred eighty".