8261398320 has 640 divisors, whose sum is σ = 31965954048. Its totient is φ = 1725235200.

The previous prime is 8261398283. The next prime is 8261398337. The reversal of 8261398320 is 238931628.

8261398320 = T₈₈₇₅ + T₈₈₇₆ + ... + T₉₀₇₉.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 113169804 + ... + 113169876.

Almost surely, 2^8261398320 is an apocalyptic number.

8261398320 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 8261398320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15982977024).

8261398320 is an abundant number, since it is smaller than the sum of its proper divisors (23704555728).

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

8261398320 is a wasteful number, since it uses less digits than its factorization.

8261398320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 221 (or 215 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 42.

The square root of 8261398320 is about 90892.2346518117. The cubic root of 8261398320 is about 2021.5501547412.

The spelling of 8261398320 in words is "eight billion, two hundred sixty-one million, three hundred ninety-eight thousand, three hundred twenty".