66916897 has 4 divisors (see below), whose sum is σ = 67060656. Its totient is φ = 66773140.

The previous prime is 66916877. The next prime is 66916903. The reversal of 66916897 is 79861966.

66916897 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 a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 79861966 = 2 ⋅39930983.

It is a cyclic number.

It is not a de Polignac number, because 66916897 - 2⁷ = 66916769 is a prime.

It is a super-2 number, since 2×66916897² = 8955742208217218, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66916877) 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, 71179 + ... + 72112.

It is an arithmetic number, because the mean of its divisors is an integer number (16765164).

Almost surely, 2^66916897 is an apocalyptic number.

It is an amenable number.

66916897 is a deficient number, since it is larger than the sum of its proper divisors (143759).

66916897 is a wasteful number, since it uses less digits than its factorization.

66916897 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 143758.

The product of its digits is 979776, while the sum is 52.

The square root of 66916897 is about 8180.2748731323. The cubic root of 66916897 is about 405.9868167721.

The spelling of 66916897 in words is "sixty-six million, nine hundred sixteen thousand, eight hundred ninety-seven".