166651509387 has 32 divisors (see below), whose sum is σ = 258968632320. Its totient is φ = 94256917920.

The previous prime is 166651509373. The next prime is 166651509389. The reversal of 166651509387 is 783905156661.

166651509387 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 166651509387 - 2¹⁶ = 166651443851 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is not an unprimeable number, because it can be changed into a prime (166651509389) 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 31 ways as a sum of consecutive naturals, for example, 1941513 + ... + 2025530.

It is an arithmetic number, because the mean of its divisors is an integer number (8092769760).

Almost surely, 2^166651509387 is an apocalyptic number.

166651509387 is a deficient number, since it is larger than the sum of its proper divisors (92317122933).

166651509387 is a wasteful number, since it uses less digits than its factorization.

166651509387 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3967143.

The product of its (nonzero) digits is 8164800, while the sum is 57.

The spelling of 166651509387 in words is "one hundred sixty-six billion, six hundred fifty-one million, five hundred nine thousand, three hundred eighty-seven".