2166778 has 8 divisors (see below), whose sum is σ = 3296160. Its totient is φ = 1068060.

The previous prime is 2166763. The next prime is 2166797. The reversal of 2166778 is 8776612.

It is a happy number.

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7488 + ... + 7771.

It is an arithmetic number, because the mean of its divisors is an integer number (412020).

2^2166778 is an apocalyptic number.

2166778 is a deficient number, since it is larger than the sum of its proper divisors (1129382).

2166778 is a wasteful number, since it uses less digits than its factorization.

2166778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15332.

The product of its digits is 28224, while the sum is 37.

The square root of 2166778 is about 1471.9979619551. The cubic root of 2166778 is about 129.4011509445.

The spelling of 2166778 in words is "two million, one hundred sixty-six thousand, seven hundred seventy-eight".