78217380 has 48 divisors (see below), whose sum is σ = 243344640. Its totient is φ = 20857824.

The previous prime is 78217367. The next prime is 78217393. The reversal of 78217380 is 8371287.

It is an interprime number because it is at equal distance from previous prime (78217367) and next prime (78217393).

It is a super-2 number, since 2×78217380² = 12235917068128800, 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 15 ways as a sum of consecutive naturals, for example, 71884 + ... + 72963.

It is an arithmetic number, because the mean of its divisors is an integer number (5069680).

Almost surely, 2^78217380 is an apocalyptic number.

It is an amenable number.

78217380 is an abundant number, since it is smaller than the sum of its proper divisors (165127260).

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

78217380 is a wasteful number, since it uses less digits than its factorization.

78217380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 144865 (or 144857 counting only the distinct ones).

The product of its (nonzero) digits is 18816, while the sum is 36.

The square root of 78217380 is about 8844.0590228695. The cubic root of 78217380 is about 427.6624190480.

The spelling of 78217380 in words is "seventy-eight million, two hundred seventeen thousand, three hundred eighty".