78390993 has 8 divisors (see below), whose sum is σ = 104748928. Its totient is φ = 52146864.

The previous prime is 78390953. The next prime is 78390997. The reversal of 78390993 is 39909387.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 78390993 - 2¹⁴ = 78374609 is a prime.

It is a super-2 number, since 2×78390993² = 12290295567052098, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78390997) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26830 + ... + 29607.

It is an arithmetic number, because the mean of its divisors is an integer number (13093616).

Almost surely, 2^78390993 is an apocalyptic number.

It is an amenable number.

78390993 is a deficient number, since it is larger than the sum of its proper divisors (26357935).

78390993 is a wasteful number, since it uses less digits than its factorization.

78390993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56903.

The product of its (nonzero) digits is 367416, while the sum is 48.

The square root of 78390993 is about 8853.8688153823. The cubic root of 78390993 is about 427.9786015010.

The spelling of 78390993 in words is "seventy-eight million, three hundred ninety thousand, nine hundred ninety-three".