20605711840 has 48 divisors (see below), whose sum is σ = 55635424992. Its totient is φ = 7064815104.

The previous prime is 20605711813. The next prime is 20605711859. The reversal of 20605711840 is 4811750602.

It is a junction number, because it is equal to n+sod(n) for n = 20605711796 and 20605711805.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9197859 + ... + 9200098.

It is an arithmetic number, because the mean of its divisors is an integer number (1159071354).

Almost surely, 2^20605711840 is an apocalyptic number.

20605711840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20605711840 is an abundant number, since it is smaller than the sum of its proper divisors (35029713152).

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

20605711840 is a wasteful number, since it uses less digits than its factorization.

20605711840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18397979 (or 18397971 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 34.

The spelling of 20605711840 in words is "twenty billion, six hundred five million, seven hundred eleven thousand, eight hundred forty".