21150442 has 4 divisors (see below), whose sum is σ = 31725666. Its totient is φ = 10575220.

The previous prime is 21150407. The next prime is 21150443. The reversal of 21150442 is 24405112.

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., 12453841 + 8696601 = 3529^2 + 2949^2 .

It is not an unprimeable number, because it can be changed into a prime (21150443) 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, 5287609 + ... + 5287612.

Almost surely, 2^21150442 is an apocalyptic number.

21150442 is a deficient number, since it is larger than the sum of its proper divisors (10575224).

21150442 is a wasteful number, since it uses less digits than its factorization.

21150442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10575223.

The product of its (nonzero) digits is 320, while the sum is 19.

The square root of 21150442 is about 4598.9609696104. The cubic root of 21150442 is about 276.5496729578.

Adding to 21150442 its reverse (24405112), we get a palindrome (45555554).

It can be divided in two parts, 211 and 50442, that added together give a cube (50653 = 37³).

The spelling of 21150442 in words is "twenty-one million, one hundred fifty thousand, four hundred forty-two".