78199993 has 4 divisors (see below), whose sum is σ = 78413440. Its totient is φ = 77986548.

The previous prime is 78199951. The next prime is 78199999. The reversal of 78199993 is 39999187.

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, and also an emirpimes, since its reverse is a distinct semiprime: 39999187 = 863 ⋅46349.

It is a cyclic number.

It is not a de Polignac number, because 78199993 - 2⁹ = 78199481 is a prime.

It is a super-2 number, since 2×78199993² = 12230477810400098, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78199999) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 106173 + ... + 106906.

It is an arithmetic number, because the mean of its divisors is an integer number (19603360).

Almost surely, 2^78199993 is an apocalyptic number.

It is an amenable number.

78199993 is a deficient number, since it is larger than the sum of its proper divisors (213447).

78199993 is a wasteful number, since it uses less digits than its factorization.

78199993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 213446.

The product of its digits is 1102248, while the sum is 55.

The square root of 78199993 is about 8843.0759919838. The cubic root of 78199993 is about 427.6307282332.

The spelling of 78199993 in words is "seventy-eight million, one hundred ninety-nine thousand, nine hundred ninety-three".