1981878 has 8 divisors (see below), whose sum is σ = 3963768. Its totient is φ = 660624.

The previous prime is 1981867. The next prime is 1981879. The reversal of 1981878 is 8781891.

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

1981878 is an admirable number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1981879) 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, 165151 + ... + 165162.

It is an arithmetic number, because the mean of its divisors is an integer number (495471).

2^1981878 is an apocalyptic number.

1981878 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

1981878 is a wasteful number, since it uses less digits than its factorization.

1981878 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 330318.

The product of its digits is 32256, while the sum is 42.

The square root of 1981878 is about 1407.7918880289. The cubic root of 1981878 is about 125.6104116621.

The spelling of 1981878 in words is "one million, nine hundred eighty-one thousand, eight hundred seventy-eight".