166988606401 has 4 divisors (see below), whose sum is σ = 167578672432. Its totient is φ = 166398540372.

The previous prime is 166988606387. The next prime is 166988606569. The reversal of 166988606401 is 104606889661.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 104606889661 = 263209 ⋅397429.

It is a cyclic number.

It is not a de Polignac number, because 166988606401 - 2⁷ = 166988606273 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166985606401) 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, 295032591 + ... + 295033156.

It is an arithmetic number, because the mean of its divisors is an integer number (41894668108).

Almost surely, 2^166988606401 is an apocalyptic number.

It is an amenable number.

166988606401 is a deficient number, since it is larger than the sum of its proper divisors (590066031).

166988606401 is an equidigital number, since it uses as much as digits as its factorization.

166988606401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 590066030.

The product of its (nonzero) digits is 2985984, while the sum is 55.

The spelling of 166988606401 in words is "one hundred sixty-six billion, nine hundred eighty-eight million, six hundred six thousand, four hundred one".