166978974469 has 4 divisors (see below), whose sum is σ = 167014896300. Its totient is φ = 166943052640.

The previous prime is 166978974467. The next prime is 166978974521. The reversal of 166978974469 is 964479879661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 964479879661 = 5657 ⋅170493173.

It can be written as a sum of positive squares in 2 ways, for example, as 102985153569 + 63993820900 = 320913^2 + 252970^2 .

It is a cyclic number.

It is not a de Polignac number, because 166978974469 - 2¹ = 166978974467 is a prime.

It is a super-2 number, since 2×166978974469² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 166978974395 and 166978974404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166978974467) 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, 17953942 + ... + 17963239.

It is an arithmetic number, because the mean of its divisors is an integer number (41753724075).

Almost surely, 2^166978974469 is an apocalyptic number.

It is an amenable number.

166978974469 is a deficient number, since it is larger than the sum of its proper divisors (35921831).

166978974469 is an equidigital number, since it uses as much as digits as its factorization.

166978974469 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35921830.

The product of its digits is 987614208, while the sum is 76.

The spelling of 166978974469 in words is "one hundred sixty-six billion, nine hundred seventy-eight million, nine hundred seventy-four thousand, four hundred sixty-nine".