247666961 has 2 divisors, whose sum is σ = 247666962. Its totient is φ = 247666960.

The previous prime is 247666901. The next prime is 247666963. The reversal of 247666961 is 169666742.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 243984400 + 3682561 = 15620^2 + 1919^2 .

It is a cyclic number.

It is not a de Polignac number, because 247666961 - 2¹⁰ = 247665937 is a prime.

It is a super-2 number, since 2×247666961² = 122677847141951042, which contains 22 as substring.

Together with 247666963, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (247666963) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 123833480 + 123833481.

It is an arithmetic number, because the mean of its divisors is an integer number (123833481).

Almost surely, 2^247666961 is an apocalyptic number.

It is an amenable number.

247666961 is a deficient number, since it is larger than the sum of its proper divisors (1).

247666961 is an equidigital number, since it uses as much as digits as its factorization.

247666961 is an evil number, because the sum of its binary digits is even.

The product of its digits is 653184, while the sum is 47.

The square root of 247666961 is about 15737.4381968604. The cubic root of 247666961 is about 627.9947673236.

The spelling of 247666961 in words is "two hundred forty-seven million, six hundred sixty-six thousand, nine hundred sixty-one".