21409485 has 32 divisors (see below), whose sum is σ = 36917760. Its totient is φ = 10559808.

The previous prime is 21409483. The next prime is 21409489. The reversal of 21409485 is 58490412.

It is not a de Polignac number, because 21409485 - 2¹ = 21409483 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21409483) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11382 + ... + 13128.

It is an arithmetic number, because the mean of its divisors is an integer number (1153680).

Almost surely, 2^21409485 is an apocalyptic number.

It is an amenable number.

21409485 is a deficient number, since it is larger than the sum of its proper divisors (15508275).

21409485 is a wasteful number, since it uses less digits than its factorization.

21409485 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1817.

The product of its (nonzero) digits is 11520, while the sum is 33.

The square root of 21409485 is about 4627.0384696910. The cubic root of 21409485 is about 277.6741217095.

Adding to 21409485 its reverse (58490412), we get a palindrome (79899897).

The spelling of 21409485 in words is "twenty-one million, four hundred nine thousand, four hundred eighty-five".