247661641 has 2 divisors, whose sum is σ = 247661642. Its totient is φ = 247661640.

The previous prime is 247661621. The next prime is 247661693. The reversal of 247661641 is 146166742.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 168896016 + 78765625 = 12996^2 + 8875^2 .

It is a cyclic number.

It is not a de Polignac number, because 247661641 - 2²⁵ = 214107209 is a prime.

It is a super-2 number, since 2×247661641² = 122672576845625762, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 247661641.

It is not a weakly prime, because it can be changed into another prime (247661611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 123830820 + 123830821.

It is an arithmetic number, because the mean of its divisors is an integer number (123830821).

Almost surely, 2^247661641 is an apocalyptic number.

It is an amenable number.

247661641 is a deficient number, since it is larger than the sum of its proper divisors (1).

247661641 is an equidigital number, since it uses as much as digits as its factorization.

247661641 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 48384, while the sum is 37.

The square root of 247661641 is about 15737.2691722548. The cubic root of 247661641 is about 627.9902707528.

The spelling of 247661641 in words is "two hundred forty-seven million, six hundred sixty-one thousand, six hundred forty-one".