78222816 has 216 divisors, whose sum is σ = 271134864. Its totient is φ = 21288960.

The previous prime is 78222787. The next prime is 78222817. The reversal of 78222816 is 61822287.

It is a happy number.

It is a super-2 number, since 2×78222816² = 12237617885939712, which contains 22 as substring.

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

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78222817) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 324456 + ... + 324696.

It is an arithmetic number, because the mean of its divisors is an integer number (1255254).

Almost surely, 2^78222816 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 78222816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (135567432).

78222816 is an abundant number, since it is smaller than the sum of its proper divisors (192912048).

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

78222816 is a wasteful number, since it uses less digits than its factorization.

78222816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 294 (or 276 counting only the distinct ones).

The product of its digits is 21504, while the sum is 36.

The square root of 78222816 is about 8844.3663424804. The cubic root of 78222816 is about 427.6723261346.

It can be divided in two parts, 7822281 and 6, that added together give a palindrome (7822287).

The spelling of 78222816 in words is "seventy-eight million, two hundred twenty-two thousand, eight hundred sixteen".