16666705387 has 4 divisors (see below), whose sum is σ = 16683224440. Its totient is φ = 16650186336.

The previous prime is 16666705379. The next prime is 16666705421. The reversal of 16666705387 is 78350766661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 78350766661 = 87911 ⋅891251.

It is a cyclic number.

It is not a de Polignac number, because 16666705387 - 2³ = 16666705379 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16666705337) 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, 8258013 + ... + 8260030.

It is an arithmetic number, because the mean of its divisors is an integer number (4170806110).

Almost surely, 2^16666705387 is an apocalyptic number.

16666705387 is a deficient number, since it is larger than the sum of its proper divisors (16519053).

16666705387 is a wasteful number, since it uses less digits than its factorization.

16666705387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16519052.

The product of its (nonzero) digits is 7620480, while the sum is 55.

The spelling of 16666705387 in words is "sixteen billion, six hundred sixty-six million, seven hundred five thousand, three hundred eighty-seven".