78028257 has 8 divisors (see below), whose sum is σ = 105068160. Its totient is φ = 51503600.

The previous prime is 78028253. The next prime is 78028261. The reversal of 78028257 is 75282087.

It is an interprime number because it is at equal distance from previous prime (78028253) and next prime (78028261).

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 78028257 - 2² = 78028253 is a prime.

It is not an unprimeable number, because it can be changed into a prime (78028253) 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, 128457 + ... + 129062.

It is an arithmetic number, because the mean of its divisors is an integer number (13133520).

Almost surely, 2^78028257 is an apocalyptic number.

It is an amenable number.

78028257 is a deficient number, since it is larger than the sum of its proper divisors (27039903).

78028257 is a wasteful number, since it uses less digits than its factorization.

78028257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 257623.

The product of its (nonzero) digits is 62720, while the sum is 39.

The square root of 78028257 is about 8833.3604590778. The cubic root of 78028257 is about 427.3174570331.

The spelling of 78028257 in words is "seventy-eight million, twenty-eight thousand, two hundred fifty-seven".