20646319680 has 672 divisors, whose sum is σ = 84560785920. Its totient is φ = 4525424640.

The previous prime is 20646319669. The next prime is 20646319691. The reversal of 20646319680 is 8691364602.

20646319680 is a `hidden beast` number, since 2 + 0 + 6 + 4 + 631 + 9 + 6 + 8 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (20646319669) and next prime (20646319691).

It is a tau number, because it is divible by the number of its divisors (672).

It is a Harshad number since it is a multiple of its sum of digits (45).

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 95 ways as a sum of consecutive naturals, for example, 66386725 + ... + 66387035.

Almost surely, 2^20646319680 is an apocalyptic number.

20646319680 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 20646319680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42280392960).

20646319680 is an abundant number, since it is smaller than the sum of its proper divisors (63914466240).

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

20646319680 is a wasteful number, since it uses less digits than its factorization.

20646319680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 467 (or 454 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 45.

The spelling of 20646319680 in words is "twenty billion, six hundred forty-six million, three hundred nineteen thousand, six hundred eighty".