21459855 has 16 divisors (see below), whose sum is σ = 35520480. Its totient is φ = 11050368.

The previous prime is 21459853. The next prime is 21459857. The reversal of 21459855 is 55895412.

It is an interprime number because it is at equal distance from previous prime (21459853) and next prime (21459857).

It is not a de Polignac number, because 21459855 - 2¹ = 21459853 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21459853) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24232 + ... + 25101.

It is an arithmetic number, because the mean of its divisors is an integer number (2220030).

Almost surely, 2^21459855 is an apocalyptic number.

21459855 is a deficient number, since it is larger than the sum of its proper divisors (14060625).

21459855 is a wasteful number, since it uses less digits than its factorization.

21459855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49370.

The product of its digits is 72000, while the sum is 39.

The square root of 21459855 is about 4632.4782784164. The cubic root of 21459855 is about 277.8917120471.

The spelling of 21459855 in words is "twenty-one million, four hundred fifty-nine thousand, eight hundred fifty-five".