78421224 has 64 divisors (see below), whose sum is σ = 224726400. Its totient is φ = 22339584.

The previous prime is 78421181. The next prime is 78421229. The reversal of 78421224 is 42212487.

It is a super-2 number, since 2×78421224² = 12299776747316352, which contains 22 as substring.

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

It is a junction number, because it is equal to n+sod(n) for n = 78421191 and 78421200.

It is not an unprimeable number, because it can be changed into a prime (78421229) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 96532 + ... + 97340.

It is an arithmetic number, because the mean of its divisors is an integer number (3511350).

Almost surely, 2^78421224 is an apocalyptic number.

It is an amenable number.

78421224 is an abundant number, since it is smaller than the sum of its proper divisors (146305176).

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

78421224 is a wasteful number, since it uses less digits than its factorization.

78421224 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1402 (or 1398 counting only the distinct ones).

The product of its digits is 7168, while the sum is 30.

The square root of 78421224 is about 8855.5758706027. The cubic root of 78421224 is about 428.0336101943.

The spelling of 78421224 in words is "seventy-eight million, four hundred twenty-one thousand, two hundred twenty-four".