1981837 has 8 divisors (see below), whose sum is σ = 2328480. Its totient is φ = 1662960.

The previous prime is 1981813. The next prime is 1981853. The reversal of 1981837 is 7381891.

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

It is a de Polignac number, because none of the positive numbers 2^k-1981837 is a prime.

1981837 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 1981796 and 1981805.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1981867) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6787 + ... + 7072.

It is an arithmetic number, because the mean of its divisors is an integer number (291060).

2^1981837 is an apocalyptic number.

It is an amenable number.

1981837 is a deficient number, since it is larger than the sum of its proper divisors (346643).

1981837 is a wasteful number, since it uses less digits than its factorization.

1981837 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13883.

The product of its digits is 12096, while the sum is 37.

The square root of 1981837 is about 1407.7773261422. Note that the first 3 decimals coincide. The cubic root of 1981837 is about 125.6095454698.

The spelling of 1981837 in words is "one million, nine hundred eighty-one thousand, eight hundred thirty-seven".