21406485 has 32 divisors (see below), whose sum is σ = 36605952. Its totient is φ = 10644480.

The previous prime is 21406481. The next prime is 21406487. The reversal of 21406485 is 58460412.

It is not a de Polignac number, because 21406485 - 2² = 21406481 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21406481) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 32055 + ... + 32715.

It is an arithmetic number, because the mean of its divisors is an integer number (1143936).

Almost surely, 2^21406485 is an apocalyptic number.

It is an amenable number.

21406485 is a deficient number, since it is larger than the sum of its proper divisors (15199467).

21406485 is a wasteful number, since it uses less digits than its factorization.

21406485 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 813.

The product of its (nonzero) digits is 7680, while the sum is 30.

The square root of 21406485 is about 4626.7142768924. The cubic root of 21406485 is about 277.6611514259.

Adding to 21406485 its reverse (58460412), we get a palindrome (79866897).

The spelling of 21406485 in words is "twenty-one million, four hundred six thousand, four hundred eighty-five".