865222400 has 324 divisors, whose sum is σ = 2600458560. Its totient is φ = 283852800.

The previous prime is 865222387. The next prime is 865222427. The reversal of 865222400 is 4222568.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 9721556 + ... + 9721644.

Almost surely, 2^865222400 is an apocalyptic number.

865222400 is a gapful number since it is divisible by the number (80) 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 865222400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1300229280).

865222400 is an abundant number, since it is smaller than the sum of its proper divisors (1735236160).

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

865222400 is a wasteful number, since it uses less digits than its factorization.

865222400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 160 (or 134 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 29.

The square root of 865222400 is about 29414.6630101383. The cubic root of 865222400 is about 952.8895952189.

Adding to 865222400 its reverse (4222568), we get a palindrome (869444968).

The spelling of 865222400 in words is "eight hundred sixty-five million, two hundred twenty-two thousand, four hundred".