21012680544 has 96 divisors (see below), whose sum is σ = 58949202816. Its totient is φ = 6530549760.

The previous prime is 21012680501. The next prime is 21012680551. The reversal of 21012680544 is 44508621012.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (96).

It is a super-3 number, since 3×21012680544³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 114459 + ... + 234789.

It is an arithmetic number, because the mean of its divisors is an integer number (614054196).

Almost surely, 2^21012680544 is an apocalyptic number.

21012680544 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21012680544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29474601408).

21012680544 is an abundant number, since it is smaller than the sum of its proper divisors (37936522272).

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

21012680544 is a wasteful number, since it uses less digits than its factorization.

21012680544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120468 (or 120460 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 33.

The spelling of 21012680544 in words is "twenty-one billion, twelve million, six hundred eighty thousand, five hundred forty-four".