811145664 has 168 divisors, whose sum is σ = 2755928448. Its totient is φ = 231724800.

The previous prime is 811145641. The next prime is 811145737. The reversal of 811145664 is 466541118.

811145664 is a `hidden beast` number, since 81 + 1 + 14 + 566 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (168).

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 105139 + ... + 112589.

It is an arithmetic number, because the mean of its divisors is an integer number (16404336).

Almost surely, 2^811145664 is an apocalyptic number.

811145664 is a gapful number since it is divisible by the number (84) 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 811145664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1377964224).

811145664 is an abundant number, since it is smaller than the sum of its proper divisors (1944782784).

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

811145664 is an equidigital number, since it uses as much as digits as its factorization.

811145664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7485 (or 7463 counting only the distinct ones).

The product of its digits is 23040, while the sum is 36.

The square root of 811145664 is about 28480.6190943947. The cubic root of 811145664 is about 932.6090317110.

The spelling of 811145664 in words is "eight hundred eleven million, one hundred forty-five thousand, six hundred sixty-four".