2152343666521 has 4 divisors (see below), whose sum is σ = 2152347689700. Its totient is φ = 2152339643344.

The previous prime is 2152343666497. The next prime is 2152343666593. The reversal of 2152343666521 is 1256663432512.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1195390168921 + 956953497600 = 1093339^2 + 978240^2 .

It is a cyclic number.

It is not a de Polignac number, because 2152343666521 - 2¹¹ = 2152343664473 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2152343666621) 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, 1058626 + ... + 2329243.

It is an arithmetic number, because the mean of its divisors is an integer number (538086922425).

Almost surely, 2^{2152343666521} is an apocalyptic number.

It is an amenable number.

2152343666521 is a deficient number, since it is larger than the sum of its proper divisors (4023179).

2152343666521 is an equidigital number, since it uses as much as digits as its factorization.

2152343666521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4023178.

The product of its digits is 1555200, while the sum is 46.

The spelling of 2152343666521 in words is "two trillion, one hundred fifty-two billion, three hundred forty-three million, six hundred sixty-six thousand, five hundred twenty-one".