78251 has 4 divisors (see below), whose sum is σ = 82872. Its totient is φ = 73632.

The previous prime is 78241. The next prime is 78259. The reversal of 78251 is 15287.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78251 is a prime.

It is a super-2 number, since 2×78251² = 12246438002, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78259) 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, 2285 + ... + 2318.

It is an arithmetic number, because the mean of its divisors is an integer number (20718).

2⁷⁸²⁵¹ is an apocalyptic number.

78251 is a deficient number, since it is larger than the sum of its proper divisors (4621).

78251 is a wasteful number, since it uses less digits than its factorization.

78251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4620.

The product of its digits is 560, while the sum is 23.

The square root of 78251 is about 279.7338020333. The cubic root of 78251 is about 42.7723683995.

The spelling of 78251 in words is "seventy-eight thousand, two hundred fifty-one".