12856867521 has 8 divisors (see below), whose sum is σ = 17156220000. Its totient is φ = 8564380032.

The previous prime is 12856867519. The next prime is 12856867523. The reversal of 12856867521 is 12576865821.

It is an interprime number because it is at equal distance from previous prime (12856867519) and next prime (12856867523).

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

It is not a de Polignac number, because 12856867521 - 2¹ = 12856867519 is a prime.

It is not an unprimeable number, because it can be changed into a prime (12856867523) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1711875 + ... + 1719368.

It is an arithmetic number, because the mean of its divisors is an integer number (2144527500).

Almost surely, 2^12856867521 is an apocalyptic number.

It is an amenable number.

12856867521 is a deficient number, since it is larger than the sum of its proper divisors (4299352479).

12856867521 is a wasteful number, since it uses less digits than its factorization.

12856867521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3432495.

The product of its digits is 1612800, while the sum is 51.

The spelling of 12856867521 in words is "twelve billion, eight hundred fifty-six million, eight hundred sixty-seven thousand, five hundred twenty-one".