21253006 has 8 divisors (see below), whose sum is σ = 32657184. Its totient is φ = 10367280.

The previous prime is 21252997. The next prime is 21253007. The reversal of 21253006 is 60035212.

It is a happy number.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21253007) by changing a digit.

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 in 3 ways as a sum of consecutive naturals, for example, 129510 + ... + 129673.

It is an arithmetic number, because the mean of its divisors is an integer number (4082148).

Almost surely, 2^21253006 is an apocalyptic number.

21253006 is a deficient number, since it is larger than the sum of its proper divisors (11404178).

21253006 is a wasteful number, since it uses less digits than its factorization.

21253006 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 259226.

The product of its (nonzero) digits is 360, while the sum is 19.

The square root of 21253006 is about 4610.0982635948. The cubic root of 21253006 is about 276.9959727809.

Adding to 21253006 its reverse (60035212), we get a palindrome (81288218).

The spelling of 21253006 in words is "twenty-one million, two hundred fifty-three thousand, six".