864821055 has 32 divisors (see below), whose sum is σ = 1587068928. Its totient is φ = 393926400.

The previous prime is 864821053. The next prime is 864821071. The reversal of 864821055 is 550128468.

It is not a de Polignac number, because 864821055 - 2¹ = 864821053 is a prime.

It is a zygodrome in base 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (864821053) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 14850 + ... + 44160.

It is an arithmetic number, because the mean of its divisors is an integer number (49595904).

Almost surely, 2^864821055 is an apocalyptic number.

864821055 is a deficient number, since it is larger than the sum of its proper divisors (722247873).

864821055 is a wasteful number, since it uses less digits than its factorization.

864821055 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29607.

The product of its (nonzero) digits is 76800, while the sum is 39.

The square root of 864821055 is about 29407.8400260883. The cubic root of 864821055 is about 952.7422355640.

The spelling of 864821055 in words is "eight hundred sixty-four million, eight hundred twenty-one thousand, fifty-five".