21541073 has 4 divisors (see below), whose sum is σ = 21800688. Its totient is φ = 21281460.

The previous prime is 21541061. The next prime is 21541097. The reversal of 21541073 is 37014512.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21541073 - 2⁸ = 21540817 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21541033) 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, 129683 + ... + 129848.

It is an arithmetic number, because the mean of its divisors is an integer number (5450172).

Almost surely, 2^21541073 is an apocalyptic number.

It is an amenable number.

21541073 is a deficient number, since it is larger than the sum of its proper divisors (259615).

21541073 is an equidigital number, since it uses as much as digits as its factorization.

21541073 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 259614.

The product of its (nonzero) digits is 840, while the sum is 23.

The square root of 21541073 is about 4641.2361499928. The cubic root of 21541073 is about 278.2418448238.

Adding to 21541073 its reverse (37014512), we get a palindrome (58555585).

The spelling of 21541073 in words is "twenty-one million, five hundred forty-one thousand, seventy-three".