21541011 has 4 divisors (see below), whose sum is σ = 28721352. Its totient is φ = 14360672.

The previous prime is 21540983. The next prime is 21541019. The reversal of 21541011 is 11014512.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21541011 - 2⁶ = 21540947 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21541019) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3590166 + ... + 3590171.

It is an arithmetic number, because the mean of its divisors is an integer number (7180338).

Almost surely, 2^21541011 is an apocalyptic number.

21541011 is a deficient number, since it is larger than the sum of its proper divisors (7180341).

21541011 is an equidigital number, since it uses as much as digits as its factorization.

21541011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7180340.

The product of its (nonzero) digits is 40, while the sum is 15.

The square root of 21541011 is about 4641.2294707329. The cubic root of 21541011 is about 278.2415778763.

Adding to 21541011 its reverse (11014512), we get a palindrome (32555523).

The spelling of 21541011 in words is "twenty-one million, five hundred forty-one thousand, eleven".