21545768 has 16 divisors (see below), whose sum is σ = 40449780. Its totient is φ = 10759168.

The previous prime is 21545759. The next prime is 21545773. The reversal of 21545768 is 86754512.

It can be written as a sum of positive squares in 2 ways, for example, as 20052484 + 1493284 = 4478^2 + 1222^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8630 + ... + 10842.

Almost surely, 2^21545768 is an apocalyptic number.

It is an amenable number.

21545768 is a deficient number, since it is larger than the sum of its proper divisors (18904012).

21545768 is a wasteful number, since it uses less digits than its factorization.

21545768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3436 (or 3432 counting only the distinct ones).

The product of its digits is 67200, while the sum is 38.

The square root of 21545768 is about 4641.7419144110. The cubic root of 21545768 is about 278.2620581556.

The spelling of 21545768 in words is "twenty-one million, five hundred forty-five thousand, seven hundred sixty-eight".