20351686687 has 4 divisors (see below), whose sum is σ = 20442950080. Its totient is φ = 20260423296.

The previous prime is 20351686549. The next prime is 20351686703. The reversal of 20351686687 is 78668615302.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20351686687 - 2¹⁹ = 20351162399 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 (20351686387) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45631362 + ... + 45631807.

It is an arithmetic number, because the mean of its divisors is an integer number (5110737520).

Almost surely, 2^20351686687 is an apocalyptic number.

20351686687 is a deficient number, since it is larger than the sum of its proper divisors (91263393).

20351686687 is an equidigital number, since it uses as much as digits as its factorization.

20351686687 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91263392.

The product of its (nonzero) digits is 2903040, while the sum is 52.

The spelling of 20351686687 in words is "twenty billion, three hundred fifty-one million, six hundred eighty-six thousand, six hundred eighty-seven".