166216431437 has 4 divisors (see below), whose sum is σ = 189961635936. Its totient is φ = 142471226940.

The previous prime is 166216431421. The next prime is 166216431463. The reversal of 166216431437 is 734134612661.

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: 734134612661 = 22481 ⋅32655781.

It is not a de Polignac number, because 166216431437 - 2⁴ = 166216431421 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 (166216431497) 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, 11872602239 + ... + 11872602252.

It is an arithmetic number, because the mean of its divisors is an integer number (47490408984).

Almost surely, 2^166216431437 is an apocalyptic number.

It is an amenable number.

166216431437 is a deficient number, since it is larger than the sum of its proper divisors (23745204499).

166216431437 is an equidigital number, since it uses as much as digits as its factorization.

166216431437 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23745204498.

The product of its digits is 435456, while the sum is 44.

The spelling of 166216431437 in words is "one hundred sixty-six billion, two hundred sixteen million, four hundred thirty-one thousand, four hundred thirty-seven".