20509857760 has 384 divisors, whose sum is σ = 59073960960. Its totient is φ = 6583762944.

The previous prime is 20509857737. The next prime is 20509857779. The reversal of 20509857760 is 6775890502.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 230447796 + ... + 230447884.

It is an arithmetic number, because the mean of its divisors is an integer number (153838440).

Almost surely, 2^20509857760 is an apocalyptic number.

20509857760 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 20509857760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29536980480).

20509857760 is an abundant number, since it is smaller than the sum of its proper divisors (38564103200).

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

20509857760 is a wasteful number, since it uses less digits than its factorization.

20509857760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 298 (or 290 counting only the distinct ones).

The product of its (nonzero) digits is 1058400, while the sum is 49.

The spelling of 20509857760 in words is "twenty billion, five hundred nine million, eight hundred fifty-seven thousand, seven hundred sixty".