21545360 has 20 divisors (see below), whose sum is σ = 50093148. Its totient is φ = 8618112.

The previous prime is 21545357. The next prime is 21545369. The reversal of 21545360 is 6354512.

It can be written as a sum of positive squares in 2 ways, for example, as 10995856 + 10549504 = 3316^2 + 3248^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is not an unprimeable number, because it can be changed into a prime (21545369) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 134579 + ... + 134738.

Almost surely, 2^21545360 is an apocalyptic number.

21545360 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21545360 is an abundant number, since it is smaller than the sum of its proper divisors (28547788).

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

21545360 is a wasteful number, since it uses less digits than its factorization.

21545360 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 269330 (or 269324 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 26.

The square root of 21545360 is about 4641.6979651847. The cubic root of 21545360 is about 278.2603017142.

Adding to 21545360 its reverse (6354512), we get a palindrome (27899872).

The spelling of 21545360 in words is "twenty-one million, five hundred forty-five thousand, three hundred sixty".