21120042 has 8 divisors (see below), whose sum is σ = 42240096. Its totient is φ = 7040012.

The previous prime is 21120041. The next prime is 21120067. The reversal of 21120042 is 24002112.

It is a sphenic number, since it is the product of 3 distinct primes.

21120042 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (21120041) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1759998 + ... + 1760009.

It is an arithmetic number, because the mean of its divisors is an integer number (5280012).

Almost surely, 2^21120042 is an apocalyptic number.

21120042 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21120042 is a wasteful number, since it uses less digits than its factorization.

21120042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3520012.

The product of its (nonzero) digits is 32, while the sum is 12.

The square root of 21120042 is about 4595.6546867666. The cubic root of 21120042 is about 276.4171124312.

Adding to 21120042 its reverse (24002112), we get a palindrome (45122154).

The spelling of 21120042 in words is "twenty-one million, one hundred twenty thousand, forty-two".