8191220736 has 88 divisors (see below), whose sum is σ = 22782029184. Its totient is φ = 2611671040.

The previous prime is 8191220731. The next prime is 8191220743. The reversal of 8191220736 is 6370221918.

It is a junction number, because it is equal to n+sod(n) for n = 8191220694 and 8191220703.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8191220731) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12691 + ... + 128621.

Almost surely, 2^8191220736 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 8191220736, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11391014592).

8191220736 is an abundant number, since it is smaller than the sum of its proper divisors (14590808448).

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

8191220736 is a wasteful number, since it uses less digits than its factorization.

8191220736 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115977 (or 115959 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 39.

The square root of 8191220736 is about 90505.3630234143. The cubic root of 8191220736 is about 2015.8097578103.

The spelling of 8191220736 in words is "eight billion, one hundred ninety-one million, two hundred twenty thousand, seven hundred thirty-six".