20867609664 has 448 divisors, whose sum is σ = 69373455360. Its totient is φ = 6147187200.

The previous prime is 20867609597. The next prime is 20867609677. The reversal of 20867609664 is 46690676802.

20867609664 is a `hidden beast` number, since 20 + 8 + 6 + 7 + 609 + 6 + 6 + 4 = 666.

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

It is a self number, because there is not a number n which added to its sum of digits gives 20867609664.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 98898519 + ... + 98898729.

Almost surely, 2^20867609664 is an apocalyptic number.

20867609664 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 20867609664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34686727680).

20867609664 is an abundant number, since it is smaller than the sum of its proper divisors (48505845696).

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

20867609664 is a wasteful number, since it uses less digits than its factorization.

20867609664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 308 (or 270 counting only the distinct ones).

The product of its (nonzero) digits is 5225472, while the sum is 54.

The spelling of 20867609664 in words is "twenty billion, eight hundred sixty-seven million, six hundred nine thousand, six hundred sixty-four".