66690831 has 8 divisors (see below), whose sum is σ = 89074944. Its totient is φ = 44383640.

The previous prime is 66690781. The next prime is 66690859. The reversal of 66690831 is 13809666.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66690831 - 2⁹ = 66690319 is a prime.

It is a super-2 number, since 2×66690831² = 8895333878941122, which contains 22 as substring.

It is a zygodrome in base 2.

It is a self number, because there is not a number n which added to its sum of digits gives 66690831.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66691831) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17175 + ... + 20696.

It is an arithmetic number, because the mean of its divisors is an integer number (11134368).

Almost surely, 2^66690831 is an apocalyptic number.

66690831 is a deficient number, since it is larger than the sum of its proper divisors (22384113).

66690831 is a wasteful number, since it uses less digits than its factorization.

66690831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38461.

The product of its (nonzero) digits is 46656, while the sum is 39.

The square root of 66690831 is about 8166.4454323775. The cubic root of 66690831 is about 405.5291179057.

The spelling of 66690831 in words is "sixty-six million, six hundred ninety thousand, eight hundred thirty-one".