247124821 has 2 divisors, whose sum is σ = 247124822. Its totient is φ = 247124820.

The previous prime is 247124807. The next prime is 247124837. The reversal of 247124821 is 128421742.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 246144721 + 980100 = 15689^2 + 990^2 .

It is a cyclic number.

It is not a de Polignac number, because 247124821 - 2²³ = 238736213 is a prime.

It is a super-2 number, since 2×247124821² = 122141354308564082, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (247124321) 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, 123562410 + 123562411.

It is an arithmetic number, because the mean of its divisors is an integer number (123562411).

Almost surely, 2^247124821 is an apocalyptic number.

It is an amenable number.

247124821 is a deficient number, since it is larger than the sum of its proper divisors (1).

247124821 is an equidigital number, since it uses as much as digits as its factorization.

247124821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7168, while the sum is 31.

The square root of 247124821 is about 15720.2042289533. The cubic root of 247124821 is about 627.5362082354.

The spelling of 247124821 in words is "two hundred forty-seven million, one hundred twenty-four thousand, eight hundred twenty-one".