7856961785 has 4 divisors (see below), whose sum is σ = 9428354148. Its totient is φ = 6285569424.

The previous prime is 7856961767. The next prime is 7856961787. The reversal of 7856961785 is 5871696587.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5871696587 = 199 ⋅29506013.

It can be written as a sum of positive squares in 2 ways, for example, as 1196606464 + 6660355321 = 34592^2 + 81611^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7856961785 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7856961787) 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, 785696174 + ... + 785696183.

It is an arithmetic number, because the mean of its divisors is an integer number (2357088537).

Almost surely, 2^7856961785 is an apocalyptic number.

It is an amenable number.

7856961785 is a deficient number, since it is larger than the sum of its proper divisors (1571392363).

7856961785 is a wasteful number, since it uses less digits than its factorization.

7856961785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1571392362.

The product of its digits is 25401600, while the sum is 62.

The square root of 7856961785 is about 88639.5046522712. The cubic root of 7856961785 is about 1988.0083931304.

The spelling of 7856961785 in words is "seven billion, eight hundred fifty-six million, nine hundred sixty-one thousand, seven hundred eighty-five".