78149 has 4 divisors (see below), whose sum is σ = 82764. Its totient is φ = 73536.

The previous prime is 78139. The next prime is 78157. The reversal of 78149 is 94187.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 94187 = 97 ⋅971.

It can be written as a sum of positive squares in 2 ways, for example, as 30625 + 47524 = 175^2 + 218^2 .

It is a cyclic number.

It is not a de Polignac number, because 78149 - 2⁸ = 77893 is a prime.

It is a super-2 number, since 2×78149² = 12214532402, which contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 78149.

It is not an unprimeable number, because it can be changed into a prime (78139) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2282 + ... + 2315.

It is an arithmetic number, because the mean of its divisors is an integer number (20691).

2⁷⁸¹⁴⁹ is an apocalyptic number.

It is an amenable number.

78149 is a deficient number, since it is larger than the sum of its proper divisors (4615).

78149 is a wasteful number, since it uses less digits than its factorization.

78149 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4614.

The product of its digits is 2016, while the sum is 29.

The square root of 78149 is about 279.5514263959. The cubic root of 78149 is about 42.7537757572.

The spelling of 78149 in words is "seventy-eight thousand, one hundred forty-nine".