811618560 has 216 divisors, whose sum is σ = 2869776000. Its totient is φ = 211685376.

The previous prime is 811618559. The next prime is 811618567. The reversal of 811618560 is 65816118.

811618560 is a `hidden beast` number, since 81 + 1 + 6 + 18 + 560 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (811618567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 540691 + ... + 542189.

It is an arithmetic number, because the mean of its divisors is an integer number (13286000).

Almost surely, 2^811618560 is an apocalyptic number.

811618560 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 811618560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1434888000).

811618560 is an abundant number, since it is smaller than the sum of its proper divisors (2058157440).

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

811618560 is a wasteful number, since it uses less digits than its factorization.

811618560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1573 (or 1556 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 36.

The square root of 811618560 is about 28488.9199514478. The cubic root of 811618560 is about 932.7902327875.

The spelling of 811618560 in words is "eight hundred eleven million, six hundred eighteen thousand, five hundred sixty".