21214042 has 4 divisors (see below), whose sum is σ = 31821066. Its totient is φ = 10607020.

The previous prime is 21214021. The next prime is 21214049. The reversal of 21214042 is 24041212.

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., 11978521 + 9235521 = 3461^2 + 3039^2 .

It is not an unprimeable number, because it can be changed into a prime (21214049) 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, 5303509 + ... + 5303512.

Almost surely, 2^21214042 is an apocalyptic number.

21214042 is a deficient number, since it is larger than the sum of its proper divisors (10607024).

21214042 is a wasteful number, since it uses less digits than its factorization.

21214042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10607023.

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 21214042 is about 4605.8703846287. The cubic root of 21214042 is about 276.8265932356.

Adding to 21214042 its reverse (24041212), we get a palindrome (45255254).

The spelling of 21214042 in words is "twenty-one million, two hundred fourteen thousand, forty-two".