21044323155 has 16 divisors (see below), whose sum is σ = 33699169440. Its totient is φ = 11214221568.

The previous prime is 21044323117. The next prime is 21044323187. The reversal of 21044323155 is 55132344012.

It is not a de Polignac number, because 21044323155 - 2²⁹ = 20507452243 is a prime.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 570100 + ... + 605889.

It is an arithmetic number, because the mean of its divisors is an integer number (2106198090).

Almost surely, 2^21044323155 is an apocalyptic number.

21044323155 is a deficient number, since it is larger than the sum of its proper divisors (12654846285).

21044323155 is a wasteful number, since it uses less digits than its factorization.

21044323155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1177190.

The product of its (nonzero) digits is 14400, while the sum is 30.

Adding to 21044323155 its reverse (55132344012), we get a palindrome (76176667167).

The spelling of 21044323155 in words is "twenty-one billion, forty-four million, three hundred twenty-three thousand, one hundred fifty-five".