20855501680 has 40 divisors (see below), whose sum is σ = 52218970272. Its totient is φ = 7700492544.

The previous prime is 20855501663. The next prime is 20855501683. The reversal of 20855501680 is 8610555802.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20855501683) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10025644 + ... + 10027723.

Almost surely, 2^20855501680 is an apocalyptic number.

20855501680 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20855501680 is an abundant number, since it is smaller than the sum of its proper divisors (31363468592).

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

20855501680 is a wasteful number, since it uses less digits than its factorization.

20855501680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20053393 (or 20053387 counting only the distinct ones).

The product of its (nonzero) digits is 96000, while the sum is 40.

The spelling of 20855501680 in words is "twenty billion, eight hundred fifty-five million, five hundred one thousand, six hundred eighty".