7781389056 has 432 divisors, whose sum is σ = 27515412288. Its totient is φ = 2064384000.

The previous prime is 7781389051. The next prime is 7781389061. The reversal of 7781389056 is 6509831877.

It is an interprime number because it is at equal distance from previous prime (7781389051) and next prime (7781389061).

It is a super-2 number, since 2×7781389056² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 7781388993 and 7781389011.

It is not an unprimeable number, because it can be changed into a prime (7781389051) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 27691636 + ... + 27691916.

It is an arithmetic number, because the mean of its divisors is an integer number (63693084).

Almost surely, 2^7781389056 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 7781389056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13757706144).

7781389056 is an abundant number, since it is smaller than the sum of its proper divisors (19734023232).

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

7781389056 is a wasteful number, since it uses less digits than its factorization.

7781389056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 428 (or 411 counting only the distinct ones).

The product of its (nonzero) digits is 2540160, while the sum is 54.

The square root of 7781389056 is about 88212.1820158645. The cubic root of 7781389056 is about 1981.6139152251.

The spelling of 7781389056 in words is "seven billion, seven hundred eighty-one million, three hundred eighty-nine thousand, fifty-six".