21985486560 has 240 divisors, whose sum is σ = 80965041696. Its totient is φ = 5607816192.

The previous prime is 21985486547. The next prime is 21985486561. The reversal of 21985486560 is 6568458912.

21985486560 is a `hidden beast` number, since 2 + 1 + 98 + 548 + 6 + 5 + 6 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a junction number, because it is equal to n+sod(n) for n = 21985486497 and 21985486506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21985486561) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 261202 + ... + 334958.

Almost surely, 2^21985486560 is an apocalyptic number.

21985486560 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 21985486560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40482520848).

21985486560 is an abundant number, since it is smaller than the sum of its proper divisors (58979555136).

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

21985486560 is a wasteful number, since it uses less digits than its factorization.

21985486560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73807 (or 73790 counting only the distinct ones).

The product of its (nonzero) digits is 4147200, while the sum is 54.

The spelling of 21985486560 in words is "twenty-one billion, nine hundred eighty-five million, four hundred eighty-six thousand, five hundred sixty".