20555471664 has 480 divisors, whose sum is σ = 76425358464. Its totient is φ = 5003182080.

The previous prime is 20555471659. The next prime is 20555471771. The reversal of 20555471664 is 46617455502.

20555471664 is a `hidden beast` number, since 20 + 5 + 554 + 7 + 16 + 64 = 666.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 11805834 + ... + 11807574.

Almost surely, 2^20555471664 is an apocalyptic number.

20555471664 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 20555471664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38212679232).

20555471664 is an abundant number, since it is smaller than the sum of its proper divisors (55869886800).

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

20555471664 is a wasteful number, since it uses less digits than its factorization.

20555471664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1845 (or 1836 counting only the distinct ones).

The product of its (nonzero) digits is 1008000, while the sum is 45.

The spelling of 20555471664 in words is "twenty billion, five hundred fifty-five million, four hundred seventy-one thousand, six hundred sixty-four".