166539452501 has 4 divisors (see below), whose sum is σ = 166551509100. Its totient is φ = 166527395904.

The previous prime is 166539452483. The next prime is 166539452507. The reversal of 166539452501 is 105254935661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 105254935661 = 5303 ⋅19848187.

It can be written as a sum of positive squares in 2 ways, for example, as 7696552900 + 158842899601 = 87730^2 + 398551^2 .

It is a cyclic number.

It is not a de Polignac number, because 166539452501 - 2⁶ = 166539452437 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166539452507) 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, 6007556 + ... + 6035213.

It is an arithmetic number, because the mean of its divisors is an integer number (41637877275).

Almost surely, 2^166539452501 is an apocalyptic number.

It is an amenable number.

166539452501 is a deficient number, since it is larger than the sum of its proper divisors (12056599).

166539452501 is a wasteful number, since it uses less digits than its factorization.

166539452501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12056598.

The product of its (nonzero) digits is 972000, while the sum is 47.

The spelling of 166539452501 in words is "one hundred sixty-six billion, five hundred thirty-nine million, four hundred fifty-two thousand, five hundred one".