21231554353544 has 16 divisors (see below), whose sum is σ = 39841503313920. Its totient is φ = 10607153469840.

The previous prime is 21231554353417. The next prime is 21231554353571. The reversal of 21231554353544 is 44535345513212.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1077952904 + ... + 1077972599.

It is an arithmetic number, because the mean of its divisors is an integer number (2490093957120).

Almost surely, 2^{21231554353544} is an apocalyptic number.

It is an amenable number.

21231554353544 is a deficient number, since it is larger than the sum of its proper divisors (18609948960376).

21231554353544 is a wasteful number, since it uses less digits than its factorization.

21231554353544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2155926740 (or 2155926736 counting only the distinct ones).

The product of its digits is 4320000, while the sum is 47.

Adding to 21231554353544 its reverse (44535345513212), we get a palindrome (65766899866756).

The spelling of 21231554353544 in words is "twenty-one trillion, two hundred thirty-one billion, five hundred fifty-four million, three hundred fifty-three thousand, five hundred forty-four".