78428689 has 8 divisors (see below), whose sum is σ = 83742912. Its totient is φ = 73273200.

The previous prime is 78428677. The next prime is 78428699. The reversal of 78428689 is 98682487.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 78428689 - 2¹³ = 78420497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78428699) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 38662 + ... + 40639.

It is an arithmetic number, because the mean of its divisors is an integer number (10467864).

Almost surely, 2^78428689 is an apocalyptic number.

It is an amenable number.

78428689 is a deficient number, since it is larger than the sum of its proper divisors (5314223).

78428689 is a wasteful number, since it uses less digits than its factorization.

78428689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79367.

The product of its digits is 1548288, while the sum is 52.

The square root of 78428689 is about 8855.9973464314. The cubic root of 78428689 is about 428.0471914221.

The spelling of 78428689 in words is "seventy-eight million, four hundred twenty-eight thousand, six hundred eighty-nine".