2117778 has 32 divisors (see below), whose sum is σ = 4804800. Its totient is φ = 616896.

The previous prime is 2117777. The next prime is 2117813. The reversal of 2117778 is 8777112.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2117777) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 768 + ... + 2196.

It is an arithmetic number, because the mean of its divisors is an integer number (150150).

2^2117778 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2117778, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2402400).

2117778 is an abundant number, since it is smaller than the sum of its proper divisors (2687022).

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

2117778 is a wasteful number, since it uses less digits than its factorization.

2117778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1466.

The product of its digits is 5488, while the sum is 33.

The square root of 2117778 is about 1455.2587398810. The cubic root of 2117778 is about 128.4182687683.

The spelling of 2117778 in words is "two million, one hundred seventeen thousand, seven hundred seventy-eight".