78531149 has 4 divisors (see below), whose sum is σ = 78675264. Its totient is φ = 78387036.

The previous prime is 78531127. The next prime is 78531151. The reversal of 78531149 is 94113587.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78531149 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 (78531119) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 71237 + ... + 72330.

It is an arithmetic number, because the mean of its divisors is an integer number (19668816).

Almost surely, 2^78531149 is an apocalyptic number.

It is an amenable number.

78531149 is a deficient number, since it is larger than the sum of its proper divisors (144115).

78531149 is a wasteful number, since it uses less digits than its factorization.

78531149 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 144114.

The product of its digits is 30240, while the sum is 38.

The square root of 78531149 is about 8861.7802387556. The cubic root of 78531149 is about 428.2335119761.

The spelling of 78531149 in words is "seventy-eight million, five hundred thirty-one thousand, one hundred forty-nine".