78216780 has 24 divisors (see below), whose sum is σ = 219007152. Its totient is φ = 20857792.

The previous prime is 78216773. The next prime is 78216781. The reversal of 78216780 is 8761287.

It is a super-2 number, since 2×78216780² = 12235729347136800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78216781) 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, 651747 + ... + 651866.

It is an arithmetic number, because the mean of its divisors is an integer number (9125298).

Almost surely, 2^78216780 is an apocalyptic number.

It is an amenable number.

78216780 is an abundant number, since it is smaller than the sum of its proper divisors (140790372).

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

78216780 is a wasteful number, since it uses less digits than its factorization.

78216780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1303625 (or 1303623 counting only the distinct ones).

The product of its (nonzero) digits is 37632, while the sum is 39.

The square root of 78216780 is about 8844.0251017283. The cubic root of 78216780 is about 427.6613255225.

The spelling of 78216780 in words is "seventy-eight million, two hundred sixteen thousand, seven hundred eighty".