21217262 has 32 divisors (see below), whose sum is σ = 36875520. Its totient is φ = 9054720.

The previous prime is 21217249. The next prime is 21217271. The reversal of 21217262 is 26271212.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 80543 + ... + 80805.

It is an arithmetic number, because the mean of its divisors is an integer number (1152360).

Almost surely, 2^21217262 is an apocalyptic number.

21217262 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21217262 is a deficient number, since it is larger than the sum of its proper divisors (15658258).

21217262 is a wasteful number, since it uses less digits than its factorization.

21217262 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 488.

The product of its digits is 672, while the sum is 23.

The square root of 21217262 is about 4606.2199252750. The cubic root of 21217262 is about 276.8405986844.

Adding to 21217262 its reverse (26271212), we get a palindrome (47488474).

The spelling of 21217262 in words is "twenty-one million, two hundred seventeen thousand, two hundred sixty-two".