21252106 has 8 divisors (see below), whose sum is σ = 32281920. Its totient is φ = 10491468.

The previous prime is 21252079. The next prime is 21252107. The reversal of 21252106 is 60125212.

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

It is not an unprimeable number, because it can be changed into a prime (21252107) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 67096 + ... + 67411.

It is an arithmetic number, because the mean of its divisors is an integer number (4035240).

Almost surely, 2^21252106 is an apocalyptic number.

21252106 is a deficient number, since it is larger than the sum of its proper divisors (11029814).

21252106 is a wasteful number, since it uses less digits than its factorization.

21252106 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 134588.

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 21252106 is about 4610.0006507592. Note that the first 3 decimals coincide. The cubic root of 21252106 is about 276.9920627475.

Adding to 21252106 its reverse (60125212), we get a palindrome (81377318).

The spelling of 21252106 in words is "twenty-one million, two hundred fifty-two thousand, one hundred six".