20909377680 has 80 divisors (see below), whose sum is σ = 66042112320. Its totient is φ = 5470626304.

The previous prime is 20909377639. The next prime is 20909377691. The reversal of 20909377680 is 8677390902.

It is a tau number, because it is divible by the number of its divisors (80).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 809190 + ... + 834629.

It is an arithmetic number, because the mean of its divisors is an integer number (825526404).

Almost surely, 2^20909377680 is an apocalyptic number.

20909377680 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20909377680 is an abundant number, since it is smaller than the sum of its proper divisors (45132734640).

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

20909377680 is a wasteful number, since it uses less digits than its factorization.

20909377680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1643888 (or 1643882 counting only the distinct ones).

The product of its (nonzero) digits is 1143072, while the sum is 51.

The spelling of 20909377680 in words is "twenty billion, nine hundred nine million, three hundred seventy-seven thousand, six hundred eighty".