21545104 has 30 divisors (see below), whose sum is σ = 48560694. Its totient is φ = 9233280.

The previous prime is 21545077. The next prime is 21545141. The reversal of 21545104 is 40154512.

It can be written as a sum of positive squares in only one way, i.e., 21344400 + 200704 = 4620^2 + 448^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12957 + ... + 14524.

Almost surely, 2^21545104 is an apocalyptic number.

It is an amenable number.

21545104 is an abundant number, since it is smaller than the sum of its proper divisors (27015590).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21545104 is a wasteful number, since it uses less digits than its factorization.

21545104 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27503 (or 27490 counting only the distinct ones).

The product of its (nonzero) digits is 800, while the sum is 22.

The square root of 21545104 is about 4641.6703889871. The cubic root of 21545104 is about 278.2591996220.

Adding to 21545104 its reverse (40154512), we get a palindrome (61699616).

The spelling of 21545104 in words is "twenty-one million, five hundred forty-five thousand, one hundred four".