66673697 has 4 divisors (see below), whose sum is σ = 68972820. Its totient is φ = 64374576.

The previous prime is 66673687. The next prime is 66673723. The reversal of 66673697 is 79637666.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 79637666 = 2 ⋅39818833.

It can be written as a sum of positive squares in 2 ways, for example, as 36192256 + 30481441 = 6016^2 + 5521^2 .

It is a cyclic number.

It is not a de Polignac number, because 66673697 - 2⁸ = 66673441 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66673657) 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, 1149518 + ... + 1149575.

It is an arithmetic number, because the mean of its divisors is an integer number (17243205).

Almost surely, 2^66673697 is an apocalyptic number.

It is an amenable number.

66673697 is a deficient number, since it is larger than the sum of its proper divisors (2299123).

66673697 is a wasteful number, since it uses less digits than its factorization.

66673697 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2299122.

The product of its digits is 1714608, while the sum is 50.

The square root of 66673697 is about 8165.3963161625. The cubic root of 66673697 is about 405.4943858397.

The spelling of 66673697 in words is "sixty-six million, six hundred seventy-three thousand, six hundred ninety-seven".