78424220 has 24 divisors (see below), whose sum is σ = 188218464. Its totient is φ = 26888256.

The previous prime is 78424183. The next prime is 78424231. The reversal of 78424220 is 2242487.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 279947 + ... + 280226.

It is an arithmetic number, because the mean of its divisors is an integer number (7842436).

Almost surely, 2^78424220 is an apocalyptic number.

78424220 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

78424220 is an abundant number, since it is smaller than the sum of its proper divisors (109794244).

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

78424220 is a wasteful number, since it uses less digits than its factorization.

78424220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 560189 (or 560187 counting only the distinct ones).

The product of its (nonzero) digits is 7168, while the sum is 29.

The square root of 78424220 is about 8855.7450279465. The cubic root of 78424220 is about 428.0390609822.

The spelling of 78424220 in words is "seventy-eight million, four hundred twenty-four thousand, two hundred twenty".