21585045 has 32 divisors (see below), whose sum is σ = 37065600. Its totient is φ = 10692864.

The previous prime is 21585041. The next prime is 21585059. The reversal of 21585045 is 54058512.

It is not a de Polignac number, because 21585045 - 2² = 21585041 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 (21585041) 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, 14391 + ... + 15819.

It is an arithmetic number, because the mean of its divisors is an integer number (1158300).

Almost surely, 2^21585045 is an apocalyptic number.

It is an amenable number.

21585045 is a deficient number, since it is larger than the sum of its proper divisors (15480555).

21585045 is a wasteful number, since it uses less digits than its factorization.

21585045 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1509.

The product of its (nonzero) digits is 8000, while the sum is 30.

The square root of 21585045 is about 4645.9708350355. The cubic root of 21585045 is about 278.4310420656.

The spelling of 21585045 in words is "twenty-one million, five hundred eighty-five thousand, forty-five".