66607831 has 4 divisors (see below), whose sum is σ = 67016632. Its totient is φ = 66199032.

The previous prime is 66607813. The next prime is 66607837. The reversal of 66607831 is 13870666.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13870666 = 2 ⋅6935333.

It is a cyclic number.

It is not a de Polignac number, because 66607831 - 2⁵ = 66607799 is a prime.

It is a super-2 number, since 2×66607831² = 8873206301049122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66607837) 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 3 ways as a sum of consecutive naturals, for example, 204156 + ... + 204481.

It is an arithmetic number, because the mean of its divisors is an integer number (16754158).

Almost surely, 2^66607831 is an apocalyptic number.

66607831 is a deficient number, since it is larger than the sum of its proper divisors (408801).

66607831 is a wasteful number, since it uses less digits than its factorization.

66607831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 408800.

The product of its (nonzero) digits is 36288, while the sum is 37.

The square root of 66607831 is about 8161.3620799472. The cubic root of 66607831 is about 405.3608144607.

The spelling of 66607831 in words is "sixty-six million, six hundred seven thousand, eight hundred thirty-one".