16375521 has 4 divisors (see below), whose sum is σ = 21834032. Its totient is φ = 10917012.

The previous prime is 16375493. The next prime is 16375531. The reversal of 16375521 is 12557361.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12557361 = 3 ⋅4185787.

It is not a de Polignac number, because 16375521 - 2¹⁰ = 16374497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16375531) 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, 2729251 + ... + 2729256.

It is an arithmetic number, because the mean of its divisors is an integer number (5458508).

Almost surely, 2^16375521 is an apocalyptic number.

It is an amenable number.

16375521 is a deficient number, since it is larger than the sum of its proper divisors (5458511).

16375521 is an equidigital number, since it uses as much as digits as its factorization.

16375521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5458510.

The product of its digits is 6300, while the sum is 30.

The square root of 16375521 is about 4046.6678885226. The cubic root of 16375521 is about 253.9403470387.

The spelling of 16375521 in words is "sixteen million, three hundred seventy-five thousand, five hundred twenty-one".