21054858 has 32 divisors (see below), whose sum is σ = 46725120. Its totient is φ = 6270960.

The previous prime is 21054851. The next prime is 21054863. The reversal of 21054858 is 85845012.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (21054851) 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, 1191 + ... + 6597.

It is an arithmetic number, because the mean of its divisors is an integer number (1460160).

Almost surely, 2^21054858 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21054858, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23362560).

21054858 is an abundant number, since it is smaller than the sum of its proper divisors (25670262).

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

21054858 is a wasteful number, since it uses less digits than its factorization.

21054858 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5482.

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

The square root of 21054858 is about 4588.5572896064. The cubic root of 21054858 is about 276.1324453594.

It can be divided in two parts, 21054 and 858, that added together give a palindrome (21912).

The spelling of 21054858 in words is "twenty-one million, fifty-four thousand, eight hundred fifty-eight".