21255455 has 8 divisors (see below), whose sum is σ = 27468672. Its totient is φ = 15696288.

The previous prime is 21255449. The next prime is 21255467. The reversal of 21255455 is 55455212.

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 21255455 - 2⁴ = 21255439 is a prime.

It is a Duffinian number.

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, 163439 + ... + 163568.

It is an arithmetic number, because the mean of its divisors is an integer number (3433584).

Almost surely, 2^21255455 is an apocalyptic number.

21255455 is a deficient number, since it is larger than the sum of its proper divisors (6213217).

21255455 is a wasteful number, since it uses less digits than its factorization.

21255455 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 327025.

The product of its digits is 10000, while the sum is 29.

The square root of 21255455 is about 4610.3638685032. The cubic root of 21255455 is about 277.0066118576.

The spelling of 21255455 in words is "twenty-one million, two hundred fifty-five thousand, four hundred fifty-five".