21276655 has 8 divisors (see below), whose sum is σ = 25701984. Its totient is φ = 16908000.

The previous prime is 21276649. The next prime is 21276667. The reversal of 21276655 is 55667212.

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

It is not a de Polignac number, because 21276655 - 2⁵ = 21276623 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21276655.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13336 + ... + 14845.

It is an arithmetic number, because the mean of its divisors is an integer number (3212748).

Almost surely, 2^21276655 is an apocalyptic number.

21276655 is a deficient number, since it is larger than the sum of its proper divisors (4425329).

21276655 is a wasteful number, since it uses less digits than its factorization.

21276655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28337.

The product of its digits is 25200, while the sum is 34.

The square root of 21276655 is about 4612.6624632635. The cubic root of 21276655 is about 277.0986758924.

It can be divided in two parts, 212 and 76655, that added together give a palindrome (76867).

The spelling of 21276655 in words is "twenty-one million, two hundred seventy-six thousand, six hundred fifty-five".