21054213 has 12 divisors (see below), whose sum is σ = 30558528. Its totient is φ = 13968360.

The previous prime is 21054199. The next prime is 21054233. The reversal of 21054213 is 31245012.

It is not a de Polignac number, because 21054213 - 2⁵ = 21054181 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21054233) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3645 + ... + 7442.

It is an arithmetic number, because the mean of its divisors is an integer number (2546544).

Almost surely, 2^21054213 is an apocalyptic number.

It is an amenable number.

21054213 is a deficient number, since it is larger than the sum of its proper divisors (9504315).

21054213 is a wasteful number, since it uses less digits than its factorization.

21054213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11304 (or 11301 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 21054213 is about 4588.4870055390. The cubic root of 21054213 is about 276.1296256262.

Adding to 21054213 its reverse (31245012), we get a palindrome (52299225).

The spelling of 21054213 in words is "twenty-one million, fifty-four thousand, two hundred thirteen".