16660332375421 has 4 divisors (see below), whose sum is σ = 19040379857632. Its totient is φ = 14280284893212.

The previous prime is 16660332375409. The next prime is 16660332375431. The reversal of 16660332375421 is 12457323306661.

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 16660332375421 - 2¹⁹ = 16660331851133 is a prime.

It is a super-2 number, since 2×16660332375421² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16660332375431) 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, 1190023741095 + ... + 1190023741108.

It is an arithmetic number, because the mean of its divisors is an integer number (4760094964408).

Almost surely, 2^{16660332375421} is an apocalyptic number.

It is an amenable number.

16660332375421 is a deficient number, since it is larger than the sum of its proper divisors (2380047482211).

16660332375421 is an equidigital number, since it uses as much as digits as its factorization.

16660332375421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2380047482210.

The product of its (nonzero) digits is 3265920, while the sum is 49.

The spelling of 16660332375421 in words is "sixteen trillion, six hundred sixty billion, three hundred thirty-two million, three hundred seventy-five thousand, four hundred twenty-one".