78223420 has 48 divisors (see below), whose sum is σ = 180931968. Its totient is φ = 28170560.

The previous prime is 78223417. The next prime is 78223427. The reversal of 78223420 is 2432287.

It is a super-2 number, since 2×78223420² = 12237806872992800, which contains 22 as substring.

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78223427) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21879 + ... + 25201.

It is an arithmetic number, because the mean of its divisors is an integer number (3769416).

Almost surely, 2^78223420 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78223420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (90465984).

78223420 is an abundant number, since it is smaller than the sum of its proper divisors (102708548).

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

78223420 is a wasteful number, since it uses less digits than its factorization.

78223420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3450 (or 3448 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 28.

The square root of 78223420 is about 8844.4004884447. The cubic root of 78223420 is about 427.6734268936.

The spelling of 78223420 in words is "seventy-eight million, two hundred twenty-three thousand, four hundred twenty".