78454949 has 4 divisors (see below), whose sum is σ = 83069964. Its totient is φ = 73839936.

The previous prime is 78454939. The next prime is 78454951. The reversal of 78454949 is 94945487.

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

It can be written as a sum of positive squares in 2 ways, for example, as 23961025 + 54493924 = 4895^2 + 7382^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78454949 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 78454897 and 78454906.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78454939) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2307482 + ... + 2307515.

It is an arithmetic number, because the mean of its divisors is an integer number (20767491).

Almost surely, 2^78454949 is an apocalyptic number.

It is an amenable number.

78454949 is a deficient number, since it is larger than the sum of its proper divisors (4615015).

78454949 is a wasteful number, since it uses less digits than its factorization.

78454949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4615014.

The product of its digits is 1451520, while the sum is 50.

The square root of 78454949 is about 8857.4798334515. The cubic root of 78454949 is about 428.0949599325.

The spelling of 78454949 in words is "seventy-eight million, four hundred fifty-four thousand, nine hundred forty-nine".