42139894 has 4 divisors (see below), whose sum is σ = 63209844. Its totient is φ = 21069946.

The previous prime is 42139879. The next prime is 42139897. The reversal of 42139894 is 49893124.

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

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42139897) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10534972 + ... + 10534975.

It is an arithmetic number, because the mean of its divisors is an integer number (15802461).

Almost surely, 2^42139894 is an apocalyptic number.

42139894 is a deficient number, since it is larger than the sum of its proper divisors (21069950).

42139894 is a wasteful number, since it uses less digits than its factorization.

42139894 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21069949.

The product of its digits is 62208, while the sum is 40.

The square root of 42139894 is about 6491.5247823605. The cubic root of 42139894 is about 347.9881695454.

The spelling of 42139894 in words is "forty-two million, one hundred thirty-nine thousand, eight hundred ninety-four".