1981847 has 4 divisors (see below), whose sum is σ = 2264976. Its totient is φ = 1698720.

The previous prime is 1981813. The next prime is 1981853. The reversal of 1981847 is 7481891.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7481891 = 941 ⋅7951.

It is a cyclic number.

It is not a de Polignac number, because 1981847 - 2¹² = 1977751 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1981847.

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 polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 141554 + ... + 141567.

It is an arithmetic number, because the mean of its divisors is an integer number (566244).

2^1981847 is an apocalyptic number.

1981847 is a deficient number, since it is larger than the sum of its proper divisors (283129).

1981847 is an equidigital number, since it uses as much as digits as its factorization.

1981847 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 283128.

The product of its digits is 16128, while the sum is 38.

The square root of 1981847 is about 1407.7808778358. The cubic root of 1981847 is about 125.6097567373.

The spelling of 1981847 in words is "one million, nine hundred eighty-one thousand, eight hundred forty-seven".