166061257 has 4 divisors (see below), whose sum is σ = 166087060. Its totient is φ = 166035456.

The previous prime is 166061237. The next prime is 166061267. The reversal of 166061257 is 752160661.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 752160661 = 7 ⋅107451523.

It can be written as a sum of positive squares in 2 ways, for example, as 112126921 + 53934336 = 10589^2 + 7344^2 .

It is a cyclic number.

It is not a de Polignac number, because 166061257 - 2¹¹ = 166059209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166061237) 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, 5533 + ... + 19045.

It is an arithmetic number, because the mean of its divisors is an integer number (41521765).

Almost surely, 2^166061257 is an apocalyptic number.

It is an amenable number.

166061257 is a deficient number, since it is larger than the sum of its proper divisors (25803).

166061257 is a wasteful number, since it uses less digits than its factorization.

166061257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25802.

The product of its (nonzero) digits is 15120, while the sum is 34.

The square root of 166061257 is about 12886.4757400928. The cubic root of 166061257 is about 549.6540601418.

The spelling of 166061257 in words is "one hundred sixty-six million, sixty-one thousand, two hundred fifty-seven".