7821239047 has 2 divisors, whose sum is σ = 7821239048. Its totient is φ = 7821239046.

The previous prime is 7821239029. The next prime is 7821239077. The reversal of 7821239047 is 7409321287.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 7821239047 - 2²⁷ = 7687021319 is a prime.

It is a super-2 number, since 2×7821239047² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 7821238994 and 7821239012.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7821239017) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3910619523 + 3910619524.

It is an arithmetic number, because the mean of its divisors is an integer number (3910619524).

Almost surely, 2^7821239047 is an apocalyptic number.

7821239047 is a deficient number, since it is larger than the sum of its proper divisors (1).

7821239047 is an equidigital number, since it uses as much as digits as its factorization.

7821239047 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 169344, while the sum is 43.

The square root of 7821239047 is about 88437.7693465863. The cubic root of 7821239047 is about 1984.9908991244.

The spelling of 7821239047 in words is "seven billion, eight hundred twenty-one million, two hundred thirty-nine thousand, forty-seven".