20855882691 has 36 divisors (see below), whose sum is σ = 35163378432. Its totient is φ = 11876899104.

The previous prime is 20855882687. The next prime is 20855882711. The reversal of 20855882691 is 19628855802.

It is a happy number.

20855882691 is a `hidden beast` number, since 2 + 0 + 8 + 558 + 82 + 6 + 9 + 1 = 666.

It is not a de Polignac number, because 20855882691 - 2² = 20855882687 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20855882791) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 48510 + ... + 209916.

It is an arithmetic number, because the mean of its divisors is an integer number (976760512).

Almost surely, 2^20855882691 is an apocalyptic number.

20855882691 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

20855882691 is a deficient number, since it is larger than the sum of its proper divisors (14307495741).

20855882691 is a wasteful number, since it uses less digits than its factorization.

20855882691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161720 (or 161710 counting only the distinct ones).

The product of its (nonzero) digits is 2764800, while the sum is 54.

The spelling of 20855882691 in words is "twenty billion, eight hundred fifty-five million, eight hundred eighty-two thousand, six hundred ninety-one".