21853410 has 64 divisors (see below), whose sum is σ = 54552960. Its totient is φ = 5598720.

The previous prime is 21853399. The next prime is 21853487. The reversal of 21853410 is 1435812.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 133989 + ... + 134151.

It is an arithmetic number, because the mean of its divisors is an integer number (852390).

Almost surely, 2^21853410 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21853410, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27276480).

21853410 is an abundant number, since it is smaller than the sum of its proper divisors (32699550).

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

21853410 is a wasteful number, since it uses less digits than its factorization.

21853410 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 323.

The product of its (nonzero) digits is 960, while the sum is 24.

The square root of 21853410 is about 4674.7630956017. The cubic root of 21853410 is about 279.5801957315.

It can be divided in two parts, 218 and 53410, that added together give a triangular number (53628 = T₃₂₇).

The spelling of 21853410 in words is "twenty-one million, eight hundred fifty-three thousand, four hundred ten".