16661121417425 has 12 divisors (see below), whose sum is σ = 20664998593536. Its totient is φ = 13325537110800.

The previous prime is 16661121417407. The next prime is 16661121417431. The reversal of 16661121417425 is 52471412116661.

It is not a de Polignac number, because 16661121417425 - 2⁶ = 16661121417361 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 16661121417425.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 83899421 + ... + 84097770.

It is an arithmetic number, because the mean of its divisors is an integer number (1722083216128).

Almost surely, 2^{16661121417425} is an apocalyptic number.

It is an amenable number.

16661121417425 is a deficient number, since it is larger than the sum of its proper divisors (4003877176111).

16661121417425 is a wasteful number, since it uses less digits than its factorization.

16661121417425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168001168 (or 168001163 counting only the distinct ones).

The product of its digits is 483840, while the sum is 47.

The spelling of 16661121417425 in words is "sixteen trillion, six hundred sixty-one billion, one hundred twenty-one million, four hundred seventeen thousand, four hundred twenty-five".