78117493 has 4 divisors (see below), whose sum is σ = 82228960. Its totient is φ = 74006028.

The previous prime is 78117467. The next prime is 78117497. The reversal of 78117493 is 39471187.

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-78117493 is a prime.

It is a super-2 number, since 2×78117493² = 12204685425210098, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78117497) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2055705 + ... + 2055742.

It is an arithmetic number, because the mean of its divisors is an integer number (20557240).

Almost surely, 2^78117493 is an apocalyptic number.

It is an amenable number.

78117493 is a deficient number, since it is larger than the sum of its proper divisors (4111467).

78117493 is a wasteful number, since it uses less digits than its factorization.

78117493 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4111466.

The product of its digits is 42336, while the sum is 40.

The square root of 78117493 is about 8838.4100945815. The cubic root of 78117493 is about 427.4802936552.

The spelling of 78117493 in words is "seventy-eight million, one hundred seventeen thousand, four hundred ninety-three".