42043994 has 4 divisors (see below), whose sum is σ = 63065994. Its totient is φ = 21021996.

The previous prime is 42043993. The next prime is 42044047. The reversal of 42043994 is 49934024.

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., 23164969 + 18879025 = 4813^2 + 4345^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (42043993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510997 + ... + 10511000.

Almost surely, 2^42043994 is an apocalyptic number.

42043994 is a deficient number, since it is larger than the sum of its proper divisors (21022000).

42043994 is a wasteful number, since it uses less digits than its factorization.

42043994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21021999.

The product of its (nonzero) digits is 31104, while the sum is 35.

The square root of 42043994 is about 6484.1340208234. The cubic root of 42043994 is about 347.7239906413.

The spelling of 42043994 in words is "forty-two million, forty-three thousand, nine hundred ninety-four".