21733540 has 12 divisors (see below), whose sum is σ = 45640476. Its totient is φ = 8693408.

The previous prime is 21733513. The next prime is 21733561. The reversal of 21733540 is 4533712.

It can be written as a sum of positive squares in 2 ways, for example, as 14561856 + 7171684 = 3816^2 + 2678^2 .

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, 543319 + ... + 543358.

It is an arithmetic number, because the mean of its divisors is an integer number (3803373).

Almost surely, 2^21733540 is an apocalyptic number.

21733540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21733540 is an abundant number, since it is smaller than the sum of its proper divisors (23906936).

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

21733540 is a wasteful number, since it uses less digits than its factorization.

21733540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1086686 (or 1086684 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 25.

The square root of 21733540 is about 4661.9244953131. The cubic root of 21733540 is about 279.0680751825.

The spelling of 21733540 in words is "twenty-one million, seven hundred thirty-three thousand, five hundred forty".