166864707397 has 4 divisors (see below), whose sum is σ = 166867664076. Its totient is φ = 166861750720.

The previous prime is 166864707389. The next prime is 166864707421. The reversal of 166864707397 is 793707468661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 793707468661 = 31 ⋅25603466731.

It can be written as a sum of positive squares in 2 ways, for example, as 48188591361 + 118676116036 = 219519^2 + 344494^2 .

It is a cyclic number.

It is not a de Polignac number, because 166864707397 - 2³ = 166864707389 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 (166864707307) 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, 1392004 + ... + 1507117.

It is an arithmetic number, because the mean of its divisors is an integer number (41716916019).

Almost surely, 2^166864707397 is an apocalyptic number.

It is an amenable number.

166864707397 is a deficient number, since it is larger than the sum of its proper divisors (2956679).

166864707397 is an equidigital number, since it uses as much as digits as its factorization.

166864707397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2956678.

The product of its (nonzero) digits is 64012032, while the sum is 64.

The spelling of 166864707397 in words is "one hundred sixty-six billion, eight hundred sixty-four million, seven hundred seven thousand, three hundred ninety-seven".