78428533 has 4 divisors (see below), whose sum is σ = 78474880. Its totient is φ = 78382188.

The previous prime is 78428513. The next prime is 78428549. The reversal of 78428533 is 33582487.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 33582487 = 47 ⋅714521.

It is a cyclic number.

It is not a de Polignac number, because 78428533 - 2⁵ = 78428501 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78428503) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20535 + ... + 24052.

It is an arithmetic number, because the mean of its divisors is an integer number (19618720).

Almost surely, 2^78428533 is an apocalyptic number.

It is an amenable number.

78428533 is a deficient number, since it is larger than the sum of its proper divisors (46347).

78428533 is a wasteful number, since it uses less digits than its factorization.

78428533 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46346.

The product of its digits is 161280, while the sum is 40.

The square root of 78428533 is about 8855.9885388363. The cubic root of 78428533 is about 428.0469076169.

It can be divided in two parts, 78428 and 533, that added together give a square (78961 = 281²).

The spelling of 78428533 in words is "seventy-eight million, four hundred twenty-eight thousand, five hundred thirty-three".