7811947047 has 4 divisors (see below), whose sum is σ = 10415929400. Its totient is φ = 5207964696.

The previous prime is 7811947043. The next prime is 7811947067. The reversal of 7811947047 is 7407491187.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7407491187 = 3 ⋅2469163729.

It is not a de Polignac number, because 7811947047 - 2² = 7811947043 is a prime.

It is a super-2 number, since 2×7811947047² (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 = 7811946987 and 7811947005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7811947043) 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, 1301991172 + ... + 1301991177.

It is an arithmetic number, because the mean of its divisors is an integer number (2603982350).

Almost surely, 2^7811947047 is an apocalyptic number.

7811947047 is a deficient number, since it is larger than the sum of its proper divisors (2603982353).

7811947047 is a wasteful number, since it uses less digits than its factorization.

7811947047 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2603982352.

The product of its (nonzero) digits is 395136, while the sum is 48.

The square root of 7811947047 is about 88385.2196184407. The cubic root of 7811947047 is about 1984.2045000865.

The spelling of 7811947047 in words is "seven billion, eight hundred eleven million, nine hundred forty-seven thousand, forty-seven".