16554430637421 has 4 divisors (see below), whose sum is σ = 22072574183232. Its totient is φ = 11036287091612.

The previous prime is 16554430637419. The next prime is 16554430637431. The reversal of 16554430637421 is 12473603445561.

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 16554430637421 - 2¹ = 16554430637419 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16554430637431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2759071772901 + ... + 2759071772906.

It is an arithmetic number, because the mean of its divisors is an integer number (5518143545808).

Almost surely, 2^{16554430637421} is an apocalyptic number.

It is an amenable number.

16554430637421 is a deficient number, since it is larger than the sum of its proper divisors (5518143545811).

16554430637421 is an equidigital number, since it uses as much as digits as its factorization.

16554430637421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5518143545810.

The product of its (nonzero) digits is 7257600, while the sum is 51.

The spelling of 16554430637421 in words is "sixteen trillion, five hundred fifty-four billion, four hundred thirty million, six hundred thirty-seven thousand, four hundred twenty-one".