21533270 has 32 divisors (see below), whose sum is σ = 44513280. Its totient is φ = 7417440.

The previous prime is 21533269. The next prime is 21533279. The reversal of 21533270 is 7233512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21533279) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3062 + ... + 7241.

It is an arithmetic number, because the mean of its divisors is an integer number (1391040).

Almost surely, 2^21533270 is an apocalyptic number.

21533270 is an abundant number, since it is smaller than the sum of its proper divisors (22980010).

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

21533270 is a wasteful number, since it uses less digits than its factorization.

21533270 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10340.

The product of its (nonzero) digits is 1260, while the sum is 23.

The square root of 21533270 is about 4640.3954572859. The cubic root of 21533270 is about 278.2082441559.

Adding to 21533270 its reverse (7233512), we get a palindrome (28766782).

The spelling of 21533270 in words is "twenty-one million, five hundred thirty-three thousand, two hundred seventy".