16549521 has 4 divisors (see below), whose sum is σ = 22066032. Its totient is φ = 11033012.

The previous prime is 16549501. The next prime is 16549523. The reversal of 16549521 is 12594561.

16549521 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

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.

It is a cyclic number.

It is not a de Polignac number, because 16549521 - 2¹⁷ = 16418449 is a prime.

It is not an unprimeable number, because it can be changed into a prime (16549523) 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, 2758251 + ... + 2758256.

It is an arithmetic number, because the mean of its divisors is an integer number (5516508).

Almost surely, 2^16549521 is an apocalyptic number.

It is an amenable number.

16549521 is a deficient number, since it is larger than the sum of its proper divisors (5516511).

16549521 is an equidigital number, since it uses as much as digits as its factorization.

16549521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5516510.

The product of its digits is 10800, while the sum is 33.

The square root of 16549521 is about 4068.1102492435. The cubic root of 16549521 is about 254.8366042818.

It can be divided in two parts, 1654 and 9521, that added together give a triangular number (11175 = T₁₄₉).

The spelling of 16549521 in words is "sixteen million, five hundred forty-nine thousand, five hundred twenty-one".