247215439 has 2 divisors, whose sum is σ = 247215440. Its totient is φ = 247215438.

The previous prime is 247215433. The next prime is 247215457. The reversal of 247215439 is 934512742.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 247215439 - 2²³ = 238826831 is a prime.

It is a super-2 number, since 2×247215439² = 122230946559925442, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 247215398 and 247215407.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (247215433) 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, 123607719 + 123607720.

It is an arithmetic number, because the mean of its divisors is an integer number (123607720).

Almost surely, 2^247215439 is an apocalyptic number.

247215439 is a deficient number, since it is larger than the sum of its proper divisors (1).

247215439 is an equidigital number, since it uses as much as digits as its factorization.

247215439 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 60480, while the sum is 37.

The square root of 247215439 is about 15723.0861792461. The cubic root of 247215439 is about 627.6129024427.

The spelling of 247215439 in words is "two hundred forty-seven million, two hundred fifteen thousand, four hundred thirty-nine".