66432161 has 4 divisors (see below), whose sum is σ = 67685652. Its totient is φ = 65178672.

The previous prime is 66432139. The next prime is 66432167. The reversal of 66432161 is 16123466.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16123466 = 2 ⋅8061733.

It can be written as a sum of positive squares in 2 ways, for example, as 29757025 + 36675136 = 5455^2 + 6056^2 .

It is a cyclic number.

It is not a de Polignac number, because 66432161 - 2¹⁸ = 66170017 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66432167) 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, 626666 + ... + 626771.

It is an arithmetic number, because the mean of its divisors is an integer number (16921413).

Almost surely, 2^66432161 is an apocalyptic number.

It is an amenable number.

66432161 is a deficient number, since it is larger than the sum of its proper divisors (1253491).

66432161 is a wasteful number, since it uses less digits than its factorization.

66432161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1253490.

The product of its digits is 5184, while the sum is 29.

The square root of 66432161 is about 8150.5926778364. The cubic root of 66432161 is about 405.0041375384.

The spelling of 66432161 in words is "sixty-six million, four hundred thirty-two thousand, one hundred sixty-one".