21339655 has 8 divisors (see below), whose sum is σ = 26091072. Its totient is φ = 16749408.

The previous prime is 21339649. The next prime is 21339671. The reversal of 21339655 is 55693312.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21339655 - 2¹¹ = 21337607 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 21339655.

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, 39999 + ... + 40528.

It is an arithmetic number, because the mean of its divisors is an integer number (3261384).

Almost surely, 2^21339655 is an apocalyptic number.

21339655 is a deficient number, since it is larger than the sum of its proper divisors (4751417).

21339655 is an equidigital number, since it uses as much as digits as its factorization.

21339655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80585.

The product of its digits is 24300, while the sum is 34.

The square root of 21339655 is about 4619.4864433181. The cubic root of 21339655 is about 277.3719020276.

The spelling of 21339655 in words is "twenty-one million, three hundred thirty-nine thousand, six hundred fifty-five".