78291216 has 30 divisors (see below), whose sum is σ = 219107070. Its totient is φ = 26097024.

The previous prime is 78291209. The next prime is 78291247. The reversal of 78291216 is 61219287.

It can be written as a sum of positive squares in only one way, i.e., 77369616 + 921600 = 8796^2 + 960^2 .

It is a super-2 number, since 2×78291216² = 12259029005517312, which contains 22 as substring.

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

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 271701 + ... + 271988.

It is an arithmetic number, because the mean of its divisors is an integer number (7303569).

Almost surely, 2^78291216 is an apocalyptic number.

It is an amenable number.

78291216 is an abundant number, since it is smaller than the sum of its proper divisors (140815854).

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

78291216 is a wasteful number, since it uses less digits than its factorization.

78291216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 543703 (or 543694 counting only the distinct ones).

The product of its digits is 12096, while the sum is 36.

The square root of 78291216 is about 8848.2323658457. The cubic root of 78291216 is about 427.7969456351.

It can be divided in two parts, 7829 and 1216, that added together give a triangular number (9045 = T₁₃₄).

The spelling of 78291216 in words is "seventy-eight million, two hundred ninety-one thousand, two hundred sixteen".