20865241660 has 48 divisors (see below), whose sum is σ = 45803874816. Its totient is φ = 7968944192.

The previous prime is 20865241643. The next prime is 20865241667. The reversal of 20865241660 is 6614256802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20865241667) 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, 218697 + ... + 299263.

It is an arithmetic number, because the mean of its divisors is an integer number (954247392).

Almost surely, 2^20865241660 is an apocalyptic number.

20865241660 is a gapful number since it is divisible by the number (20) 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 20865241660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22901937408).

20865241660 is an abundant number, since it is smaller than the sum of its proper divisors (24938633156).

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

20865241660 is a wasteful number, since it uses less digits than its factorization.

20865241660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81162 (or 81160 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 40.

The spelling of 20865241660 in words is "twenty billion, eight hundred sixty-five million, two hundred forty-one thousand, six hundred sixty".