16541721 has 12 divisors (see below), whose sum is σ = 27307072. Its totient is φ = 9452376.

The previous prime is 16541699. The next prime is 16541743. The reversal of 16541721 is 12714561.

It is a happy number.

16541721 is a `hidden beast` number, since 1 + 654 + 1 + 7 + 2 + 1 = 666.

16541721 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 an interprime number because it is at equal distance from previous prime (16541699) and next prime (16541743).

It is not a de Polignac number, because 16541721 - 2⁷ = 16541593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16541521) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 131221 + ... + 131346.

Almost surely, 2^16541721 is an apocalyptic number.

It is an amenable number.

16541721 is a deficient number, since it is larger than the sum of its proper divisors (10765351).

16541721 is a wasteful number, since it uses less digits than its factorization.

16541721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 262580 (or 262577 counting only the distinct ones).

The product of its digits is 1680, while the sum is 27.

The square root of 16541721 is about 4067.1514601746. The cubic root of 16541721 is about 254.7965620780.

It can be divided in two parts, 1654 and 1721, that added together give a cube (3375 = 15³).

The spelling of 16541721 in words is "sixteen million, five hundred forty-one thousand, seven hundred twenty-one".