7820642447 has 4 divisors (see below), whose sum is σ = 8280680256. Its totient is φ = 7360604640.

The previous prime is 7820642419. The next prime is 7820642461. The reversal of 7820642447 is 7442460287.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7442460287 = 53 ⋅140423779.

It is a cyclic number.

It is not a de Polignac number, because 7820642447 - 2⁸ = 7820642191 is a prime.

It is a super-2 number, since 2×7820642447² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 7820642398 and 7820642407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7820642147) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 230018879 + ... + 230018912.

It is an arithmetic number, because the mean of its divisors is an integer number (2070170064).

Almost surely, 2^7820642447 is an apocalyptic number.

7820642447 is a deficient number, since it is larger than the sum of its proper divisors (460037809).

7820642447 is a wasteful number, since it uses less digits than its factorization.

7820642447 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 460037808.

The product of its (nonzero) digits is 602112, while the sum is 44.

The square root of 7820642447 is about 88434.3962890006. The cubic root of 7820642447 is about 1984.9404264871.

The spelling of 7820642447 in words is "seven billion, eight hundred twenty million, six hundred forty-two thousand, four hundred forty-seven".