247081981 has 2 divisors, whose sum is σ = 247081982. Its totient is φ = 247081980.

The previous prime is 247081957. The next prime is 247082021. The reversal of 247081981 is 189180742.

It is a happy number.

It is an a-pointer prime, because the next prime (247082021) can be obtained adding 247081981 to its sum of digits (40).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 194156356 + 52925625 = 13934^2 + 7275^2 .

It is a cyclic number.

It is not a de Polignac number, because 247081981 - 2⁷ = 247081853 is a prime.

It is a super-2 number, since 2×247081981² = 122099010669768722, which contains 22 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 (247081951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 123540990 + 123540991.

It is an arithmetic number, because the mean of its divisors is an integer number (123540991).

Almost surely, 2^247081981 is an apocalyptic number.

It is an amenable number.

247081981 is a deficient number, since it is larger than the sum of its proper divisors (1).

247081981 is an equidigital number, since it uses as much as digits as its factorization.

247081981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32256, while the sum is 40.

The square root of 247081981 is about 15718.8415921785. The cubic root of 247081981 is about 627.4999442337.

The spelling of 247081981 in words is "two hundred forty-seven million, eighty-one thousand, nine hundred eighty-one".