166742137 has 4 divisors (see below), whose sum is σ = 176550516. Its totient is φ = 156933760.

The previous prime is 166742131. The next prime is 166742153. The reversal of 166742137 is 731247661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 731247661 = 19 ⋅38486719.

It can be written as a sum of positive squares in 2 ways, for example, as 133148521 + 33593616 = 11539^2 + 5796^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-166742137 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 166742096 and 166742105.

It is not an unprimeable number, because it can be changed into a prime (166742131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4904164 + ... + 4904197.

It is an arithmetic number, because the mean of its divisors is an integer number (44137629).

Almost surely, 2^166742137 is an apocalyptic number.

166742137 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

166742137 is a deficient number, since it is larger than the sum of its proper divisors (9808379).

166742137 is an equidigital number, since it uses as much as digits as its factorization.

166742137 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9808378.

The product of its digits is 42336, while the sum is 37.

The square root of 166742137 is about 12912.8671099799. The cubic root of 166742137 is about 550.4042614643.

Adding to 166742137 its reverse (731247661), we get a palindrome (897989798).

The spelling of 166742137 in words is "one hundred sixty-six million, seven hundred forty-two thousand, one hundred thirty-seven".