858993664 has 44 divisors (see below), whose sum is σ = 1722288484. Its totient is φ = 428212224.

The previous prime is 858993617. The next prime is 858993679. The reversal of 858993664 is 466399858.

It can be written as a sum of positive squares in 2 ways, for example, as 193766400 + 665227264 = 13920^2 + 25792^2 .

It is a super-2 number, since 2×858993664² = 1475740229584289792, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 858993599 and 858993608.

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 3 ways as a sum of consecutive naturals, for example, 405472 + ... + 407584.

Almost surely, 2^858993664 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 858993664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (861144242).

858993664 is an abundant number, since it is smaller than the sum of its proper divisors (863294820).

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

858993664 is a wasteful number, since it uses less digits than its factorization.

858993664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2530 (or 2512 counting only the distinct ones).

The product of its digits is 11197440, while the sum is 58.

The square root of 858993664 is about 29308.5936885413. The cubic root of 858993664 is about 950.5974686706.

The spelling of 858993664 in words is "eight hundred fifty-eight million, nine hundred ninety-three thousand, six hundred sixty-four".