21054216 has 32 divisors (see below), whose sum is σ = 52842240. Its totient is φ = 6990528.

The previous prime is 21054199. The next prime is 21054233. The reversal of 21054216 is 61245012.

It is an interprime number because it is at equal distance from previous prime (21054199) and next prime (21054233).

It is a super-2 number, since 2×21054216² = 886560022749312, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21054192 and 21054201.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5065 + ... + 8231.

It is an arithmetic number, because the mean of its divisors is an integer number (1651320).

Almost surely, 2^21054216 is an apocalyptic number.

It is an amenable number.

21054216 is an abundant number, since it is smaller than the sum of its proper divisors (31788024).

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

21054216 is a wasteful number, since it uses less digits than its factorization.

21054216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3453 (or 3449 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 21054216 is about 4588.4873324441. The cubic root of 21054216 is about 276.1296387414.

Adding to 21054216 its reverse (61245012), we get a palindrome (82299228).

The spelling of 21054216 in words is "twenty-one million, fifty-four thousand, two hundred sixteen".