7788861 has 12 divisors (see below), whose sum is σ = 11334492. Its totient is φ = 5153856.

The previous prime is 7788857. The next prime is 7788871. The reversal of 7788861 is 1688877.

It can be written as a sum of positive squares in 2 ways, for example, as 4384836 + 3404025 = 2094^2 + 1845^2 .

It is not a de Polignac number, because 7788861 - 2² = 7788857 is a prime.

7788861 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7788821) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1926 + ... + 4391.

It is an arithmetic number, because the mean of its divisors is an integer number (944541).

Almost surely, 2^7788861 is an apocalyptic number.

It is an amenable number.

7788861 is a deficient number, since it is larger than the sum of its proper divisors (3545631).

7788861 is a wasteful number, since it uses less digits than its factorization.

7788861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6460 (or 6457 counting only the distinct ones).

The product of its digits is 150528, while the sum is 45.

The square root of 7788861 is about 2790.8530953814. The cubic root of 7788861 is about 198.2247982459.

It can be divided in two parts, 7788 and 861, that added together give a square (8649 = 93²).

The spelling of 7788861 in words is "seven million, seven hundred eighty-eight thousand, eight hundred sixty-one".