21140735851687 has 4 divisors (see below), whose sum is σ = 21145023168696. Its totient is φ = 21136448534680.

The previous prime is 21140735851679. The next prime is 21140735851693. The reversal of 21140735851687 is 78615853704112.

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 21140735851687 - 2³ = 21140735851679 is a prime.

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21140735851087) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2143651108 + ... + 2143660969.

It is an arithmetic number, because the mean of its divisors is an integer number (5286255792174).

Almost surely, 2^{21140735851687} is an apocalyptic number.

21140735851687 is a deficient number, since it is larger than the sum of its proper divisors (4287317009).

21140735851687 is an equidigital number, since it uses as much as digits as its factorization.

21140735851687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4287317008.

The product of its (nonzero) digits is 11289600, while the sum is 58.

The spelling of 21140735851687 in words is "twenty-one trillion, one hundred forty billion, seven hundred thirty-five million, eight hundred fifty-one thousand, six hundred eighty-seven".