66161677 has 4 divisors (see below), whose sum is σ = 66187836. Its totient is φ = 66135520.

The previous prime is 66161633. The next prime is 66161687. The reversal of 66161677 is 77616166.

66161677 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 77616166 = 2 ⋅38808083.

It can be written as a sum of positive squares in 2 ways, for example, as 13439556 + 52722121 = 3666^2 + 7261^2 .

It is a cyclic number.

It is not a de Polignac number, because 66161677 - 2¹⁹ = 65637389 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 (66161617) 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, 8824 + ... + 14497.

It is an arithmetic number, because the mean of its divisors is an integer number (16546959).

Almost surely, 2^66161677 is an apocalyptic number.

It is an amenable number.

66161677 is a deficient number, since it is larger than the sum of its proper divisors (26159).

66161677 is a wasteful number, since it uses less digits than its factorization.

66161677 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26158.

The product of its digits is 63504, while the sum is 40.

The square root of 66161677 is about 8133.9828497483. The cubic root of 66161677 is about 404.4537206347.

The spelling of 66161677 in words is "sixty-six million, one hundred sixty-one thousand, six hundred seventy-seven".