78220278 has 12 divisors (see below), whose sum is σ = 169477308. Its totient is φ = 26073420.

The previous prime is 78220271. The next prime is 78220291. The reversal of 78220278 is 87202287.

It is a super-2 number, since 2×78220278² = 12236823780794568, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78220271) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2172768 + ... + 2172803.

It is an arithmetic number, because the mean of its divisors is an integer number (14123109).

Almost surely, 2^78220278 is an apocalyptic number.

78220278 is an abundant number, since it is smaller than the sum of its proper divisors (91257030).

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

78220278 is a wasteful number, since it uses less digits than its factorization.

78220278 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4345579 (or 4345576 counting only the distinct ones).

The product of its (nonzero) digits is 25088, while the sum is 36.

The square root of 78220278 is about 8844.2228601500. Note that the first 3 decimals coincide. The cubic root of 78220278 is about 427.6677006976.

Subtracting 78220278 from its reverse (87202287), we obtain a square (8982009 = 2997²).

The spelling of 78220278 in words is "seventy-eight million, two hundred twenty thousand, two hundred seventy-eight".