21000541250544 has 80 divisors (see below), whose sum is σ = 55676204828160. Its totient is φ = 6816958686720.

The previous prime is 21000541250543. The next prime is 21000541250603. The reversal of 21000541250544 is 44505214500012.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000541250543) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8677624 + ... + 10830615.

It is an arithmetic number, because the mean of its divisors is an integer number (695952560352).

Almost surely, 2^{21000541250544} is an apocalyptic number.

21000541250544 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21000541250544 is an abundant number, since it is smaller than the sum of its proper divisors (34675663577616).

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

21000541250544 is a wasteful number, since it uses less digits than its factorization.

21000541250544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19508838 (or 19508832 counting only the distinct ones).

The product of its (nonzero) digits is 32000, while the sum is 33.

Adding to 21000541250544 its reverse (44505214500012), we get a palindrome (65505755750556).

The spelling of 21000541250544 in words is "twenty-one trillion, five hundred forty-one million, two hundred fifty thousand, five hundred forty-four".