21534212 has 24 divisors (see below), whose sum is σ = 44459520. Its totient is φ = 8930880.

The previous prime is 21534209. The next prime is 21534221. The reversal of 21534212 is 21243512.

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, 11537 + ... + 13272.

It is an arithmetic number, because the mean of its divisors is an integer number (1852480).

Almost surely, 2^21534212 is an apocalyptic number.

It is an amenable number.

21534212 is an abundant number, since it is smaller than the sum of its proper divisors (22925308).

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

21534212 is a wasteful number, since it uses less digits than its factorization.

21534212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24851 (or 24849 counting only the distinct ones).

The product of its digits is 480, while the sum is 20.

The square root of 21534212 is about 4640.4969561460. The cubic root of 21534212 is about 278.2123009534.

Adding to 21534212 its reverse (21243512), we get a palindrome (42777724).

The spelling of 21534212 in words is "twenty-one million, five hundred thirty-four thousand, two hundred twelve".