2159654778 has 32 divisors (see below), whose sum is σ = 4801494720. Its totient is φ = 719545680.

The previous prime is 2159654729. The next prime is 2159654801. The reversal of 2159654778 is 8774569512.

2159654778 is a `hidden beast` number, since 2 + 1 + 5 + 96 + 547 + 7 + 8 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 123393 + ... + 139803.

It is an arithmetic number, because the mean of its divisors is an integer number (150046710).

Almost surely, 2^2159654778 is an apocalyptic number.

2159654778 is an abundant number, since it is smaller than the sum of its proper divisors (2641839942).

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

2159654778 is a wasteful number, since it uses less digits than its factorization.

2159654778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18859 (or 18853 counting only the distinct ones).

The product of its digits is 4233600, while the sum is 54.

The square root of 2159654778 is about 46472.0860086999. The cubic root of 2159654778 is about 1292.5919438451.

The spelling of 2159654778 in words is "two billion, one hundred fifty-nine million, six hundred fifty-four thousand, seven hundred seventy-eight".