66916081 has 16 divisors (see below), whose sum is σ = 72160000. Its totient is φ = 61865856.

The previous prime is 66916067. The next prime is 66916099. The reversal of 66916081 is 18061966.

It is a cyclic number.

It is not a de Polignac number, because 66916081 - 2¹⁷ = 66785009 is a prime.

It is a super-2 number, since 2×66916081² = 8955523792797122, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66916081.

It is not an unprimeable number, because it can be changed into a prime (66916181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 163405 + ... + 163813.

It is an arithmetic number, because the mean of its divisors is an integer number (4510000).

Almost surely, 2^66916081 is an apocalyptic number.

It is an amenable number.

66916081 is a deficient number, since it is larger than the sum of its proper divisors (5243919).

66916081 is a wasteful number, since it uses less digits than its factorization.

66916081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 616.

The product of its (nonzero) digits is 15552, while the sum is 37.

The square root of 66916081 is about 8180.2249969056. The cubic root of 66916081 is about 405.9851665332.

The spelling of 66916081 in words is "sixty-six million, nine hundred sixteen thousand, eighty-one".