168520042 has 4 divisors (see below), whose sum is σ = 252780066. Its totient is φ = 84260020.

The previous prime is 168520039. The next prime is 168520049. The reversal of 168520042 is 240025861.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 240025861 = 23 ⋅10435907.

It can be written as a sum of positive squares in only one way, i.e., 120758121 + 47761921 = 10989^2 + 6911^2 .

It is not an unprimeable number, because it can be changed into a prime (168520049) 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 as a sum of consecutive naturals, namely, 42130009 + ... + 42130012.

Almost surely, 2^168520042 is an apocalyptic number.

168520042 is a deficient number, since it is larger than the sum of its proper divisors (84260024).

168520042 is an equidigital number, since it uses as much as digits as its factorization.

168520042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84260023.

The product of its (nonzero) digits is 3840, while the sum is 28.

The square root of 168520042 is about 12981.5269517881. The cubic root of 168520042 is about 552.3535966109.

The spelling of 168520042 in words is "one hundred sixty-eight million, five hundred twenty thousand, forty-two".