21025366560 has 1152 divisors, whose sum is σ = 89286624000. Its totient is φ = 4598415360.

The previous prime is 21025366507. The next prime is 21025366591. The reversal of 21025366560 is 6566352012.

It is a happy number.

21025366560 is a `hidden beast` number, since 2 + 1 + 0 + 2 + 536 + 65 + 60 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 288018684 + ... + 288018756.

It is an arithmetic number, because the mean of its divisors is an integer number (77505750).

Almost surely, 2^21025366560 is an apocalyptic number.

21025366560 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 21025366560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44643312000).

21025366560 is an abundant number, since it is smaller than the sum of its proper divisors (68261257440).

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

21025366560 is a wasteful number, since it uses less digits than its factorization.

21025366560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167 (or 142 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 36.

The spelling of 21025366560 in words is "twenty-one billion, twenty-five million, three hundred sixty-six thousand, five hundred sixty".