16661337421 has 8 divisors (see below), whose sum is σ = 16987229280. Its totient is φ = 16335872592.

The previous prime is 16661337401. The next prime is 16661337431. The reversal of 16661337421 is 12473316661.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 16661337421 - 2¹¹ = 16661335373 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16661337401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27391 + ... + 184588.

It is an arithmetic number, because the mean of its divisors is an integer number (2123403660).

Almost surely, 2^16661337421 is an apocalyptic number.

It is an amenable number.

16661337421 is a deficient number, since it is larger than the sum of its proper divisors (325891859).

16661337421 is a wasteful number, since it uses less digits than its factorization.

16661337421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 213515.

The product of its digits is 108864, while the sum is 40.

The spelling of 16661337421 in words is "sixteen billion, six hundred sixty-one million, three hundred thirty-seven thousand, four hundred twenty-one".