864545220 has 576 divisors, whose sum is σ = 3564288000. Its totient is φ = 167650560.

The previous prime is 864545197. The next prime is 864545221. The reversal of 864545220 is 22545468.

It is a happy number.

864545220 is a `hidden beast` number, since 8 + 645 + 4 + 5 + 2 + 2 + 0 = 666.

It is a super-3 number, since 3×864545220³ (a number of 28 digits) contains 333 as substring.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (864545221) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 12903627 + ... + 12903693.

It is an arithmetic number, because the mean of its divisors is an integer number (6188000).

Almost surely, 2^864545220 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 864545220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1782144000).

864545220 is an abundant number, since it is smaller than the sum of its proper divisors (2699742780).

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

864545220 is a wasteful number, since it uses less digits than its factorization.

864545220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133 (or 114 counting only the distinct ones).

The product of its (nonzero) digits is 76800, while the sum is 36.

The square root of 864545220 is about 29403.1498312681. The cubic root of 864545220 is about 952.6409322951.

The spelling of 864545220 in words is "eight hundred sixty-four million, five hundred forty-five thousand, two hundred twenty".