21054885 has 16 divisors (see below), whose sum is σ = 33868800. Its totient is φ = 11168960.

The previous prime is 21054883. The next prime is 21054889. The reversal of 21054885 is 58845012.

It is not a de Polignac number, because 21054885 - 2¹ = 21054883 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21054881) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 810 + ... + 6539.

It is an arithmetic number, because the mean of its divisors is an integer number (2116800).

Almost surely, 2^21054885 is an apocalyptic number.

It is an amenable number.

21054885 is a deficient number, since it is larger than the sum of its proper divisors (12813915).

21054885 is a wasteful number, since it uses less digits than its factorization.

21054885 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7548.

The product of its (nonzero) digits is 12800, while the sum is 33.

The square root of 21054885 is about 4588.5602317067. The cubic root of 21054885 is about 276.1325633935.

Adding to 21054885 its reverse (58845012), we get a palindrome (79899897).

The spelling of 21054885 in words is "twenty-one million, fifty-four thousand, eight hundred eighty-five".