20861971750 has 32 divisors (see below), whose sum is σ = 40751605440. Its totient is φ = 7981969600.

The previous prime is 20861971723. The next prime is 20861971751. The reversal of 20861971750 is 5717916802.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (46).

It is a self number, because there is not a number n which added to its sum of digits gives 20861971750.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20861971751) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 1808335 + ... + 1819834.

It is an arithmetic number, because the mean of its divisors is an integer number (1273487670).

Almost surely, 2^20861971750 is an apocalyptic number.

20861971750 is a deficient number, since it is larger than the sum of its proper divisors (19889633690).

20861971750 is a wasteful number, since it uses less digits than its factorization.

20861971750 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3628209 (or 3628199 counting only the distinct ones).

The product of its (nonzero) digits is 211680, while the sum is 46.

The spelling of 20861971750 in words is "twenty billion, eight hundred sixty-one million, nine hundred seventy-one thousand, seven hundred fifty".