78218481 has 48 divisors (see below), whose sum is σ = 123503040. Its totient is φ = 43585920.

The previous prime is 78218477. The next prime is 78218521. The reversal of 78218481 is 18481287.

It is a happy number.

It is not a de Polignac number, because 78218481 - 2² = 78218477 is a prime.

It is a super-2 number, since 2×78218481² = 12236261539894722, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78218471) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1664200 + ... + 1664246.

It is an arithmetic number, because the mean of its divisors is an integer number (2572980).

Almost surely, 2^78218481 is an apocalyptic number.

It is an amenable number.

78218481 is a deficient number, since it is larger than the sum of its proper divisors (45284559).

78218481 is a wasteful number, since it uses less digits than its factorization.

78218481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 174 (or 127 counting only the distinct ones).

The product of its digits is 28672, while the sum is 39.

The square root of 78218481 is about 8844.1212678253. The cubic root of 78218481 is about 427.6644256528.

The spelling of 78218481 in words is "seventy-eight million, two hundred eighteen thousand, four hundred eighty-one".