21338755 has 8 divisors (see below), whose sum is σ = 25631424. Its totient is φ = 17054400.

The previous prime is 21338749. The next prime is 21338761. The reversal of 21338755 is 55783312.

It is an interprime number because it is at equal distance from previous prime (21338749) and next prime (21338761).

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

It is not a de Polignac number, because 21338755 - 2³ = 21338747 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 21338755.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 8215 + ... + 10495.

It is an arithmetic number, because the mean of its divisors is an integer number (3203928).

Almost surely, 2^21338755 is an apocalyptic number.

21338755 is a deficient number, since it is larger than the sum of its proper divisors (4292669).

21338755 is a wasteful number, since it uses less digits than its factorization.

21338755 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4157.

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

The square root of 21338755 is about 4619.3890288652. The cubic root of 21338755 is about 277.3680025859.

The spelling of 21338755 in words is "twenty-one million, three hundred thirty-eight thousand, seven hundred fifty-five".