21541960 has 64 divisors (see below), whose sum is σ = 53369280. Its totient is φ = 7760640.

The previous prime is 21541939. The next prime is 21541963. The reversal of 21541960 is 6914512.

It is not an unprimeable number, because it can be changed into a prime (21541963) 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, 75979 + ... + 76261.

It is an arithmetic number, because the mean of its divisors is an integer number (833895).

Almost surely, 2^21541960 is an apocalyptic number.

21541960 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21541960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26684640).

21541960 is an abundant number, since it is smaller than the sum of its proper divisors (31827320).

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

21541960 is a wasteful number, since it uses less digits than its factorization.

21541960 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 478 (or 474 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 21541960 is about 4641.3317054483. The cubic root of 21541960 is about 278.2456638402.

It can be divided in two parts, 2154 and 1960, that added together give a palindrome (4114).

The spelling of 21541960 in words is "twenty-one million, five hundred forty-one thousand, nine hundred sixty".