2123778678 has 24 divisors (see below), whose sum is σ = 4941036792. Its totient is φ = 606793824.

The previous prime is 2123778677. The next prime is 2123778689. The reversal of 2123778678 is 8768773212.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 2123778678.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2123778677) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3611575 + ... + 3612162.

It is an arithmetic number, because the mean of its divisors is an integer number (205876533).

Almost surely, 2^2123778678 is an apocalyptic number.

2123778678 is an abundant number, since it is smaller than the sum of its proper divisors (2817258114).

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

2123778678 is a wasteful number, since it uses less digits than its factorization.

2123778678 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7223756 (or 7223749 counting only the distinct ones).

The product of its digits is 1580544, while the sum is 51.

The square root of 2123778678 is about 46084.4732854787. The cubic root of 2123778678 is about 1285.3944451646.

The spelling of 2123778678 in words is "two billion, one hundred twenty-three million, seven hundred seventy-eight thousand, six hundred seventy-eight".