21838160 has 40 divisors (see below), whose sum is σ = 52530120. Its totient is φ = 8433152.

The previous prime is 21838153. The next prime is 21838171. The reversal of 21838160 is 6183812.

It can be written as a sum of positive squares in 4 ways, for example, as 9193024 + 12645136 = 3032^2 + 3556^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2387 + ... + 7026.

It is an arithmetic number, because the mean of its divisors is an integer number (1313253).

Almost surely, 2^21838160 is an apocalyptic number.

21838160 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21838160 is an abundant number, since it is smaller than the sum of its proper divisors (30691960).

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

21838160 is a wasteful number, since it uses less digits than its factorization.

21838160 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9455 (or 9449 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 29.

The square root of 21838160 is about 4673.1317122461. The cubic root of 21838160 is about 279.5151473001.

The spelling of 21838160 in words is "twenty-one million, eight hundred thirty-eight thousand, one hundred sixty".