865513216 has 36 divisors (see below), whose sum is σ = 1731983400. Its totient is φ = 431670272.

The previous prime is 865513189. The next prime is 865513219. The reversal of 865513216 is 612315568.

It is a super-2 number, since 2×865513216² = 1498226254141325312, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (865513219) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 103230 + ... + 111298.

It is an arithmetic number, because the mean of its divisors is an integer number (48110650).

Almost surely, 2^865513216 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 865513216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (865991700).

865513216 is an abundant number, since it is smaller than the sum of its proper divisors (866470184).

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

865513216 is an equidigital number, since it uses as much as digits as its factorization.

865513216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8504 (or 8490 counting only the distinct ones).

The product of its digits is 43200, while the sum is 37.

The square root of 865513216 is about 29419.6059796864. The cubic root of 865513216 is about 952.9963440727.

The spelling of 865513216 in words is "eight hundred sixty-five million, five hundred thirteen thousand, two hundred sixteen".