21212675 has 12 divisors (see below), whose sum is σ = 28695336. Its totient is φ = 15427200.

The previous prime is 21212663. The next prime is 21212677. The reversal of 21212675 is 57621212.

It is a de Polignac number, because none of the positive numbers 2^k-21212675 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21212677) 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 11 ways as a sum of consecutive naturals, for example, 38294 + ... + 38843.

It is an arithmetic number, because the mean of its divisors is an integer number (2391278).

Almost surely, 2^21212675 is an apocalyptic number.

21212675 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21212675 is a deficient number, since it is larger than the sum of its proper divisors (7482661).

21212675 is a wasteful number, since it uses less digits than its factorization.

21212675 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77158 (or 77153 counting only the distinct ones).

The product of its digits is 1680, while the sum is 26.

The square root of 21212675 is about 4605.7219846621. The cubic root of 21212675 is about 276.8206470156.

Adding to 21212675 its reverse (57621212), we get a palindrome (78833887).

The spelling of 21212675 in words is "twenty-one million, two hundred twelve thousand, six hundred seventy-five".