2158798 has 4 divisors (see below), whose sum is σ = 3238200. Its totient is φ = 1079398.

The previous prime is 2158781. The next prime is 2158801. The reversal of 2158798 is 8978512.

It is a semiprime because it is the product of two primes.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 2158798.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 539698 + ... + 539701.

It is an arithmetic number, because the mean of its divisors is an integer number (809550).

2^2158798 is an apocalyptic number.

2158798 is a deficient number, since it is larger than the sum of its proper divisors (1079402).

2158798 is a wasteful number, since it uses less digits than its factorization.

2158798 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1079401.

The product of its digits is 40320, while the sum is 40.

The square root of 2158798 is about 1469.2848600595. The cubic root of 2158798 is about 129.2420988926.

The spelling of 2158798 in words is "two million, one hundred fifty-eight thousand, seven hundred ninety-eight".