21670356871 has 8 divisors (see below), whose sum is σ = 22001540400. Its totient is φ = 21340842432.

The previous prime is 21670356857. The next prime is 21670356893. The reversal of 21670356871 is 17865307612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21670356871 - 2²¹ = 21668259719 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21670356971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 391096 + ... + 443053.

It is an arithmetic number, because the mean of its divisors is an integer number (2750192550).

Almost surely, 2^21670356871 is an apocalyptic number.

21670356871 is a deficient number, since it is larger than the sum of its proper divisors (331183529).

21670356871 is an equidigital number, since it uses as much as digits as its factorization.

21670356871 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 834545.

The product of its (nonzero) digits is 423360, while the sum is 46.

The spelling of 21670356871 in words is "twenty-one billion, six hundred seventy million, three hundred fifty-six thousand, eight hundred seventy-one".