20661538750 has 80 divisors (see below), whose sum is σ = 40637291904. Its totient is φ = 7866000000.

The previous prime is 20661538741. The next prime is 20661538753. The reversal of 20661538750 is 5783516602.

It is a junction number, because it is equal to n+sod(n) for n = 20661538697 and 20661538706.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20661538753) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 2359380 + ... + 2368120.

Almost surely, 2^20661538750 is an apocalyptic number.

20661538750 is a deficient number, since it is larger than the sum of its proper divisors (19975753154).

20661538750 is an equidigital number, since it uses as much as digits as its factorization.

20661538750 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8855 (or 8840 counting only the distinct ones).

The product of its (nonzero) digits is 302400, while the sum is 43.

The spelling of 20661538750 in words is "twenty billion, six hundred sixty-one million, five hundred thirty-eight thousand, seven hundred fifty".