166644872531381 has 8 divisors (see below), whose sum is σ = 166748925863424. Its totient is φ = 166540835298240.

The previous prime is 166644872531363. The next prime is 166644872531387. The reversal of 166644872531381 is 183135278446661.

It is a happy number.

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 166644872531381 - 2¹⁸ = 166644872269237 is a prime.

It is a super-2 number, since 2×166644872531381² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166644872531387) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16717730 + ... + 24754236.

It is an arithmetic number, because the mean of its divisors is an integer number (20843615732928).

Almost surely, 2^{166644872531381} is an apocalyptic number.

It is an amenable number.

166644872531381 is a deficient number, since it is larger than the sum of its proper divisors (104053332043).

166644872531381 is a wasteful number, since it uses less digits than its factorization.

166644872531381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8049451.

The product of its digits is 139345920, while the sum is 65.

The spelling of 166644872531381 in words is "one hundred sixty-six trillion, six hundred forty-four billion, eight hundred seventy-two million, five hundred thirty-one thousand, three hundred eighty-one".