20681139843 has 48 divisors (see below), whose sum is σ = 37315323136. Its totient is φ = 10745887680.

The previous prime is 20681139827. The next prime is 20681139847. The reversal of 20681139843 is 34893118602.

20681139843 is a `hidden beast` number, since 206 + 8 + 11 + 398 + 43 = 666.

It is not a de Polignac number, because 20681139843 - 2⁴ = 20681139827 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20681139847) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 133573 + ... + 243318.

Almost surely, 2^20681139843 is an apocalyptic number.

20681139843 is a deficient number, since it is larger than the sum of its proper divisors (16634183293).

20681139843 is a wasteful number, since it uses less digits than its factorization.

20681139843 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 376984 (or 376981 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 45.

The spelling of 20681139843 in words is "twenty billion, six hundred eighty-one million, one hundred thirty-nine thousand, eight hundred forty-three".