21454216 has 32 divisors (see below), whose sum is σ = 47975040. Its totient is φ = 8794368.

The previous prime is 21454163. The next prime is 21454217. The reversal of 21454216 is 61245412.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21454217) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7041 + ... + 9616.

It is an arithmetic number, because the mean of its divisors is an integer number (1499220).

Almost surely, 2^21454216 is an apocalyptic number.

It is an amenable number.

21454216 is an abundant number, since it is smaller than the sum of its proper divisors (26520824).

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

21454216 is a wasteful number, since it uses less digits than its factorization.

21454216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16693 (or 16689 counting only the distinct ones).

The product of its digits is 1920, while the sum is 25.

The square root of 21454216 is about 4631.8696009279. The cubic root of 21454216 is about 277.8673694061.

Adding to 21454216 its reverse (61245412), we get a palindrome (82699628).

The spelling of 21454216 in words is "twenty-one million, four hundred fifty-four thousand, two hundred sixteen".