78199381 has 4 divisors (see below), whose sum is σ = 84214732. Its totient is φ = 72184032.

The previous prime is 78199349. The next prime is 78199393. The reversal of 78199381 is 18399187.

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 10400625 + 67798756 = 3225^2 + 8234^2 .

It is a cyclic number.

It is not a de Polignac number, because 78199381 - 2⁵ = 78199349 is a prime.

It is a super-2 number, since 2×78199381² = 12230286377566322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78199321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3007656 + ... + 3007681.

It is an arithmetic number, because the mean of its divisors is an integer number (21053683).

Almost surely, 2^78199381 is an apocalyptic number.

It is an amenable number.

78199381 is a deficient number, since it is larger than the sum of its proper divisors (6015351).

78199381 is a wasteful number, since it uses less digits than its factorization.

78199381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6015350.

The product of its digits is 108864, while the sum is 46.

The square root of 78199381 is about 8843.0413885721. The cubic root of 78199381 is about 427.6296126718.

The spelling of 78199381 in words is "seventy-eight million, one hundred ninety-nine thousand, three hundred eighty-one".