247242521 has 2 divisors, whose sum is σ = 247242522. Its totient is φ = 247242520.

The previous prime is 247242517. The next prime is 247242557. The reversal of 247242521 is 125242742.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 156250000 + 90992521 = 12500^2 + 9539^2 .

It is a cyclic number.

It is not a de Polignac number, because 247242521 - 2² = 247242517 is a prime.

It is a super-2 number, since 2×247242521² = 122257728380870882, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (247242511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 123621260 + 123621261.

It is an arithmetic number, because the mean of its divisors is an integer number (123621261).

Almost surely, 2^247242521 is an apocalyptic number.

It is an amenable number.

247242521 is a deficient number, since it is larger than the sum of its proper divisors (1).

247242521 is an equidigital number, since it uses as much as digits as its factorization.

247242521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8960, while the sum is 29.

The square root of 247242521 is about 15723.9473733538. The cubic root of 247242521 is about 627.6358195551.

The spelling of 247242521 in words is "two hundred forty-seven million, two hundred forty-two thousand, five hundred twenty-one".