20487681709991 has 16 divisors (see below), whose sum is σ = 20602189123200. Its totient is φ = 20373483333600.

The previous prime is 20487681709961. The next prime is 20487681710009. The reversal of 20487681709991 is 19990718678402.

It is a cyclic number.

It is not a de Polignac number, because 20487681709991 - 2⁶ = 20487681709927 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20487681709961) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 471925076 + ... + 471968486.

It is an arithmetic number, because the mean of its divisors is an integer number (1287636820200).

Almost surely, 2^{20487681709991} is an apocalyptic number.

20487681709991 is a deficient number, since it is larger than the sum of its proper divisors (114507413209).

20487681709991 is a wasteful number, since it uses less digits than its factorization.

20487681709991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46910.

The product of its (nonzero) digits is 109734912, while the sum is 71.

The spelling of 20487681709991 in words is "twenty trillion, four hundred eighty-seven billion, six hundred eighty-one million, seven hundred nine thousand, nine hundred ninety-one".