78158242 has 4 divisors (see below), whose sum is σ = 117237366. Its totient is φ = 39079120.

The previous prime is 78158239. The next prime is 78158251. The reversal of 78158242 is 24285187.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 76195441 + 1962801 = 8729^2 + 1401^2 .

It is a super-2 number, since 2×78158242² = 12217421585061128, which contains 22 as substring.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 19539559 + ... + 19539562.

Almost surely, 2^78158242 is an apocalyptic number.

78158242 is a deficient number, since it is larger than the sum of its proper divisors (39079124).

78158242 is a wasteful number, since it uses less digits than its factorization.

78158242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39079123.

The product of its digits is 35840, while the sum is 37.

The square root of 78158242 is about 8840.7150163321. The cubic root of 78158242 is about 427.5546106267.

It can be divided in two parts, 78158 and 242, that added together give a square (78400 = 280²).

The spelling of 78158242 in words is "seventy-eight million, one hundred fifty-eight thousand, two hundred forty-two".