21541542 has 32 divisors (see below), whose sum is σ = 47672064. Its totient is φ = 6434400.

The previous prime is 21541537. The next prime is 21541543. The reversal of 21541542 is 24514512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21541543) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 2388 + ... + 6984.

It is an arithmetic number, because the mean of its divisors is an integer number (1489752).

Almost surely, 2^21541542 is an apocalyptic number.

21541542 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 21541542, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23836032).

21541542 is an abundant number, since it is smaller than the sum of its proper divisors (26130522).

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

21541542 is a wasteful number, since it uses less digits than its factorization.

21541542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4684.

The product of its digits is 1600, while the sum is 24.

The square root of 21541542 is about 4641.2866750504. The cubic root of 21541542 is about 278.2438641364.

The spelling of 21541542 in words is "twenty-one million, five hundred forty-one thousand, five hundred forty-two".