21261054620032 has 64 divisors (see below), whose sum is σ = 43273499673600. Its totient is φ = 10400425173504.

The previous prime is 21261054619979. The next prime is 21261054620093. The reversal of 21261054620032 is 23002645016212.

It is a tau number, because it is divible by the number of its divisors (64).

It is a self number, because there is not a number n which added to its sum of digits gives 21261054620032.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15331993 + ... + 16661095.

It is an arithmetic number, because the mean of its divisors is an integer number (676148432400).

Almost surely, 2^{21261054620032} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21261054620032, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21636749836800).

21261054620032 is an abundant number, since it is smaller than the sum of its proper divisors (22012445053568).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21261054620032 is a wasteful number, since it uses less digits than its factorization.

21261054620032 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1331823 (or 1331811 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 34.

Adding to 21261054620032 its reverse (23002645016212), we get a palindrome (44263699636244).

The spelling of 21261054620032 in words is "twenty-one trillion, two hundred sixty-one billion, fifty-four million, six hundred twenty thousand, thirty-two".