78309228 has 24 divisors (see below), whose sum is σ = 182988288. Its totient is φ = 26064976.

The previous prime is 78309223. The next prime is 78309229. The reversal of 78309228 is 82290387.

It is a super-2 number, since 2×78309228² = 12264670379911968, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78309223) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4525 + ... + 13307.

It is an arithmetic number, because the mean of its divisors is an integer number (7624512).

Almost surely, 2^78309228 is an apocalyptic number.

It is an amenable number.

78309228 is an abundant number, since it is smaller than the sum of its proper divisors (104679060).

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

78309228 is a wasteful number, since it uses less digits than its factorization.

78309228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9533 (or 9531 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 39.

The square root of 78309228 is about 8849.2501377235. The cubic root of 78309228 is about 427.8297500293.

The spelling of 78309228 in words is "seventy-eight million, three hundred nine thousand, two hundred twenty-eight".