78454993 has 4 divisors (see below), whose sum is σ = 78888628. Its totient is φ = 78021360.

The previous prime is 78454991. The next prime is 78455021. The reversal of 78454993 is 39945487.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 39945487 = 317 ⋅126011.

It can be written as a sum of positive squares in 2 ways, for example, as 17114769 + 61340224 = 4137^2 + 7832^2 .

It is a cyclic number.

It is not a de Polignac number, because 78454993 - 2¹ = 78454991 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78454991) 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, 216546 + ... + 216907.

It is an arithmetic number, because the mean of its divisors is an integer number (19722157).

Almost surely, 2^78454993 is an apocalyptic number.

It is an amenable number.

78454993 is a deficient number, since it is larger than the sum of its proper divisors (433635).

78454993 is a wasteful number, since it uses less digits than its factorization.

78454993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 433634.

The product of its digits is 1088640, while the sum is 49.

The square root of 78454993 is about 8857.4823172276. The cubic root of 78454993 is about 428.0950399622.

The spelling of 78454993 in words is "seventy-eight million, four hundred fifty-four thousand, nine hundred ninety-three".