21152242 has 4 divisors (see below), whose sum is σ = 31728366. Its totient is φ = 10576120.

The previous prime is 21152239. The next prime is 21152291. The reversal of 21152242 is 24225112.

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., 18498601 + 2653641 = 4301^2 + 1629^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5288059 + ... + 5288062.

Almost surely, 2^21152242 is an apocalyptic number.

21152242 is a deficient number, since it is larger than the sum of its proper divisors (10576124).

21152242 is a wasteful number, since it uses less digits than its factorization.

21152242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10576123.

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

The square root of 21152242 is about 4599.1566618240. The cubic root of 21152242 is about 276.5575179521.

Adding to 21152242 its reverse (24225112), we get a palindrome (45377354).

The spelling of 21152242 in words is "twenty-one million, one hundred fifty-two thousand, two hundred forty-two".