21534330 has 16 divisors (see below), whose sum is σ = 51682464. Its totient is φ = 5742480.

The previous prime is 21534329. The next prime is 21534349. The reversal of 21534330 is 3343512.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21534297 and 21534306.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 358876 + ... + 358935.

It is an arithmetic number, because the mean of its divisors is an integer number (3230154).

Almost surely, 2^21534330 is an apocalyptic number.

21534330 is an abundant number, since it is smaller than the sum of its proper divisors (30148134).

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

21534330 is a wasteful number, since it uses less digits than its factorization.

21534330 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 717821.

The product of its (nonzero) digits is 1080, while the sum is 21.

The square root of 21534330 is about 4640.5096702841. The cubic root of 21534330 is about 278.2128091213.

Adding to 21534330 its reverse (3343512), we get a palindrome (24877842).

The spelling of 21534330 in words is "twenty-one million, five hundred thirty-four thousand, three hundred thirty".