78390228 has 24 divisors (see below), whose sum is σ = 209040832. Its totient is φ = 22397184.

The previous prime is 78390217. The next prime is 78390239. The reversal of 78390228 is 82209387.

It is an interprime number because it is at equal distance from previous prime (78390217) and next prime (78390239).

It is a super-2 number, since 2×78390228² = 12290055691783968, which contains 22 as substring.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors.

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, 466525 + ... + 466692.

Almost surely, 2^78390228 is an apocalyptic number.

It is an amenable number.

78390228 is an abundant number, since it is smaller than the sum of its proper divisors (130650604).

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

78390228 is a wasteful number, since it uses less digits than its factorization.

78390228 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 933231 (or 933229 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 39.

The square root of 78390228 is about 8853.8256138237. The cubic root of 78390228 is about 427.9772093143.

The spelling of 78390228 in words is "seventy-eight million, three hundred ninety thousand, two hundred twenty-eight".