7856840988 has 36 divisors (see below), whose sum is σ = 20344750608. Its totient is φ = 2555069760.

The previous prime is 7856840983. The next prime is 7856841011. The reversal of 7856840988 is 8890486587.

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×7856840988² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7856840983) 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, 2660056 + ... + 2663007.

Almost surely, 2^7856840988 is an apocalyptic number.

It is an amenable number.

7856840988 is an abundant number, since it is smaller than the sum of its proper divisors (12487909620).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

7856840988 is a wasteful number, since it uses less digits than its factorization.

7856840988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5323114 (or 5323109 counting only the distinct ones).

The product of its (nonzero) digits is 30965760, while the sum is 63.

The square root of 7856840988 is about 88638.8232548244. The cubic root of 7856840988 is about 1987.9982048546.

The spelling of 7856840988 in words is "seven billion, eight hundred fifty-six million, eight hundred forty thousand, nine hundred eighty-eight".