21354042 has 16 divisors (see below), whose sum is σ = 42805152. Its totient is φ = 7101840.

The previous prime is 21354019. The next prime is 21354049. The reversal of 21354042 is 24045312.

It is not an unprimeable number, because it can be changed into a prime (21354049) 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 in 7 ways as a sum of consecutive naturals, for example, 1009 + ... + 6612.

It is an arithmetic number, because the mean of its divisors is an integer number (2675322).

Almost surely, 2^21354042 is an apocalyptic number.

21354042 is an abundant number, since it is smaller than the sum of its proper divisors (21451110).

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

21354042 is a wasteful number, since it uses less digits than its factorization.

21354042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8093.

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 21354042 is about 4621.0433886732. The cubic root of 21354042 is about 277.4342218900.

Adding to 21354042 its reverse (24045312), we get a palindrome (45399354).

The spelling of 21354042 in words is "twenty-one million, three hundred fifty-four thousand, forty-two".