66616131 has 4 divisors (see below), whose sum is σ = 88821512. Its totient is φ = 44410752.

The previous prime is 66616129. The next prime is 66616139. The reversal of 66616131 is 13161666.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 66616131 - 2¹ = 66616129 is a prime.

It is a super-2 number, since 2×66616131² = 8875417818818322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66616139) 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, 11102686 + ... + 11102691.

It is an arithmetic number, because the mean of its divisors is an integer number (22205378).

Almost surely, 2^66616131 is an apocalyptic number.

66616131 is a deficient number, since it is larger than the sum of its proper divisors (22205381).

66616131 is a wasteful number, since it uses less digits than its factorization.

66616131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22205380.

The product of its digits is 3888, while the sum is 30.

The square root of 66616131 is about 8161.8705576602. The cubic root of 66616131 is about 405.3776510947.

Adding to 66616131 its reverse (13161666), we get a palindrome (79777797).

The spelling of 66616131 in words is "sixty-six million, six hundred sixteen thousand, one hundred thirty-one".