15543500221 has 16 divisors (see below), whose sum is σ = 16584099840. Its totient is φ = 14525699760.

The previous prime is 15543500209. The next prime is 15543500227. The reversal of 15543500221 is 12200534551.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15543500221 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 15543500221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15543500227) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1069876 + ... + 1084306.

It is an arithmetic number, because the mean of its divisors is an integer number (1036506240).

Almost surely, 2^15543500221 is an apocalyptic number.

It is an amenable number.

15543500221 is a deficient number, since it is larger than the sum of its proper divisors (1040599619).

15543500221 is a wasteful number, since it uses less digits than its factorization.

15543500221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15216.

The product of its (nonzero) digits is 6000, while the sum is 28.

The spelling of 15543500221 in words is "fifteen billion, five hundred forty-three million, five hundred thousand, two hundred twenty-one".