1981147 has 8 divisors (see below), whose sum is σ = 2295776. Its totient is φ = 1674432.

The previous prime is 1981141. The next prime is 1981153. The reversal of 1981147 is 7411891.

It is an interprime number because it is at equal distance from previous prime (1981141) and next prime (1981153).

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1981147 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1981141) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1428 + ... + 2449.

It is an arithmetic number, because the mean of its divisors is an integer number (286972).

2^1981147 is an apocalyptic number.

1981147 is a deficient number, since it is larger than the sum of its proper divisors (314629).

1981147 is an equidigital number, since it uses as much as digits as its factorization.

1981147 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3957.

The product of its digits is 2016, while the sum is 31.

The square root of 1981147 is about 1407.5322376415. The cubic root of 1981147 is about 125.5949662945.

The spelling of 1981147 in words is "one million, nine hundred eighty-one thousand, one hundred forty-seven".