21133541 has 8 divisors (see below), whose sum is σ = 24828384. Its totient is φ = 17734320.

The previous prime is 21133523. The next prime is 21133559. The reversal of 21133541 is 14533112.

It is an interprime number because it is at equal distance from previous prime (21133523) and next prime (21133559).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21133541 - 2⁶ = 21133477 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21133561) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 73751 + ... + 74036.

It is an arithmetic number, because the mean of its divisors is an integer number (3103548).

Almost surely, 2^21133541 is an apocalyptic number.

It is an amenable number.

21133541 is a deficient number, since it is larger than the sum of its proper divisors (3694843).

21133541 is a wasteful number, since it uses less digits than its factorization.

21133541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 147811.

The product of its digits is 360, while the sum is 20.

The square root of 21133541 is about 4597.1231221276. The cubic root of 21133541 is about 276.4759911006.

Adding to 21133541 its reverse (14533112), we get a palindrome (35666653).

The spelling of 21133541 in words is "twenty-one million, one hundred thirty-three thousand, five hundred forty-one".