21545308 has 12 divisors (see below), whose sum is σ = 37993032. Its totient is φ = 10690160.

The previous prime is 21545263. The next prime is 21545309. The reversal of 21545308 is 80354512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21545309) 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, 20035 + ... + 21082.

It is an arithmetic number, because the mean of its divisors is an integer number (3166086).

Almost surely, 2^21545308 is an apocalyptic number.

It is an amenable number.

21545308 is a deficient number, since it is larger than the sum of its proper divisors (16447724).

21545308 is a wasteful number, since it uses less digits than its factorization.

21545308 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41252 (or 41250 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 28.

The square root of 21545308 is about 4641.6923637828. The cubic root of 21545308 is about 278.2600778524.

The spelling of 21545308 in words is "twenty-one million, five hundred forty-five thousand, three hundred eight".