21069544 has 32 divisors (see below), whose sum is σ = 41164200. Its totient is φ = 10097920.

The previous prime is 21069487. The next prime is 21069547. The reversal of 21069544 is 44596012.

It can be written as a sum of positive squares in 4 ways, for example, as 20593444 + 476100 = 4538^2 + 690^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21069547) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 45474 + ... + 45934.

Almost surely, 2^21069544 is an apocalyptic number.

It is an amenable number.

21069544 is a deficient number, since it is larger than the sum of its proper divisors (20094656).

21069544 is a wasteful number, since it uses less digits than its factorization.

21069544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 693 (or 689 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 21069544 is about 4590.1572957797. The cubic root of 21069544 is about 276.1966322656.

The spelling of 21069544 in words is "twenty-one million, sixty-nine thousand, five hundred forty-four".