21041555321 has 4 divisors (see below), whose sum is σ = 21141278544. Its totient is φ = 20941832100.

The previous prime is 21041555239. The next prime is 21041555323. The reversal of 21041555321 is 12355514012.

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 21041555321 - 2²² = 21037361017 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21041555323) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 49861295 + ... + 49861716.

It is an arithmetic number, because the mean of its divisors is an integer number (5285319636).

Almost surely, 2^21041555321 is an apocalyptic number.

It is an amenable number.

21041555321 is a deficient number, since it is larger than the sum of its proper divisors (99723223).

21041555321 is an equidigital number, since it uses as much as digits as its factorization.

21041555321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99723222.

The product of its (nonzero) digits is 6000, while the sum is 29.

The spelling of 21041555321 in words is "twenty-one billion, forty-one million, five hundred fifty-five thousand, three hundred twenty-one".