21685530010580 has 12 divisors (see below), whose sum is σ = 45539613022260. Its totient is φ = 8674212004224.

The previous prime is 21685530010561. The next prime is 21685530010589. The reversal of 21685530010580 is 8501003558612.

It can be written as a sum of positive squares in 2 ways, for example, as 17261465614864 + 4424064395716 = 4154692^2 + 2103346^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21685530010589) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 542138250245 + ... + 542138250284.

It is an arithmetic number, because the mean of its divisors is an integer number (3794967751855).

Almost surely, 2^{21685530010580} is an apocalyptic number.

21685530010580 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21685530010580 is an abundant number, since it is smaller than the sum of its proper divisors (23854083011680).

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

21685530010580 is a wasteful number, since it uses less digits than its factorization.

21685530010580 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1084276500538 (or 1084276500536 counting only the distinct ones).

The product of its (nonzero) digits is 288000, while the sum is 44.

The spelling of 21685530010580 in words is "twenty-one trillion, six hundred eighty-five billion, five hundred thirty million, ten thousand, five hundred eighty".