20705438780 has 48 divisors (see below), whose sum is σ = 48336685824. Its totient is φ = 7398466560.

The previous prime is 20705438737. The next prime is 20705438791. The reversal of 20705438780 is 8783450702.

It is a happy number.

It is a congruent number.

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 15 ways as a sum of consecutive naturals, for example, 1276397 + ... + 1292516.

It is an arithmetic number, because the mean of its divisors is an integer number (1007014288).

Almost surely, 2^20705438780 is an apocalyptic number.

20705438780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20705438780 is an abundant number, since it is smaller than the sum of its proper divisors (27631247044).

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

20705438780 is a wasteful number, since it uses less digits than its factorization.

20705438780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2568966 (or 2568964 counting only the distinct ones).

The product of its (nonzero) digits is 376320, while the sum is 44.

The spelling of 20705438780 in words is "twenty billion, seven hundred five million, four hundred thirty-eight thousand, seven hundred eighty".