166452006521 has 4 divisors (see below), whose sum is σ = 166879904100. Its totient is φ = 166024108944.

The previous prime is 166452006509. The next prime is 166452006533. The reversal of 166452006521 is 125600254661.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (166452006509) and next prime (166452006533).

It can be written as a sum of positive squares in 2 ways, for example, as 33474361600 + 132977644921 = 182960^2 + 364661^2 .

It is a cyclic number.

It is not a de Polignac number, because 166452006521 - 2¹⁴ = 166451990137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166452006221) 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, 213948206 + ... + 213948983.

It is an arithmetic number, because the mean of its divisors is an integer number (41719976025).

Almost surely, 2^166452006521 is an apocalyptic number.

It is an amenable number.

166452006521 is a deficient number, since it is larger than the sum of its proper divisors (427897579).

166452006521 is an equidigital number, since it uses as much as digits as its factorization.

166452006521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 427897578.

The product of its (nonzero) digits is 86400, while the sum is 38.

The spelling of 166452006521 in words is "one hundred sixty-six billion, four hundred fifty-two million, six thousand, five hundred twenty-one".