2158778 has 8 divisors (see below), whose sum is σ = 3342720. Its totient is φ = 1044540.

The previous prime is 2158771. The next prime is 2158781. The reversal of 2158778 is 8778512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (2158771) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17348 + ... + 17471.

It is an arithmetic number, because the mean of its divisors is an integer number (417840).

2^2158778 is an apocalyptic number.

2158778 is a deficient number, since it is larger than the sum of its proper divisors (1183942).

2158778 is a wasteful number, since it uses less digits than its factorization.

2158778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34852.

The product of its digits is 31360, while the sum is 38.

The square root of 2158778 is about 1469.2780540116. The cubic root of 2158778 is about 129.2416997739.

The spelling of 2158778 in words is "two million, one hundred fifty-eight thousand, seven hundred seventy-eight".