1981247 has 2 divisors, whose sum is σ = 1981248. Its totient is φ = 1981246.

The previous prime is 1981237. The next prime is 1981267. The reversal of 1981247 is 7421891.

It is a weak prime.

It is an emirp because it is prime and its reverse (7421891) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1981247 - 2⁸ = 1980991 is a prime.

It is a super-3 number, since 3×1981247³ = 23331202365277668669, which contains 333 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1981237) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 990623 + 990624.

It is an arithmetic number, because the mean of its divisors is an integer number (990624).

2^1981247 is an apocalyptic number.

1981247 is a deficient number, since it is larger than the sum of its proper divisors (1).

1981247 is an equidigital number, since it uses as much as digits as its factorization.

1981247 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4032, while the sum is 32.

The square root of 1981247 is about 1407.5677603583. The cubic root of 1981247 is about 125.5970794282.

The spelling of 1981247 in words is "one million, nine hundred eighty-one thousand, two hundred forty-seven".