21485205 has 24 divisors (see below), whose sum is σ = 42561792. Its totient is φ = 9821664.

The previous prime is 21485203. The next prime is 21485213. The reversal of 21485205 is 50258412.

It is a happy number.

It is not a de Polignac number, because 21485205 - 2¹ = 21485203 is a prime.

It is a super-2 number, since 2×21485205² = 923228067784050, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21485203) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 33789 + ... + 34418.

It is an arithmetic number, because the mean of its divisors is an integer number (1773408).

Almost surely, 2^21485205 is an apocalyptic number.

It is an amenable number.

21485205 is a deficient number, since it is larger than the sum of its proper divisors (21076587).

21485205 is a wasteful number, since it uses less digits than its factorization.

21485205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68225 (or 68222 counting only the distinct ones).

The product of its (nonzero) digits is 3200, while the sum is 27.

The square root of 21485205 is about 4635.2135873118. The cubic root of 21485205 is about 278.0010912091.

The spelling of 21485205 in words is "twenty-one million, four hundred eighty-five thousand, two hundred five".