66564666031 has 4 divisors (see below), whose sum is σ = 66572554752. Its totient is φ = 66556777312.

The previous prime is 66564666029. The next prime is 66564666037. The reversal of 66564666031 is 13066646566.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 66564666031 - 2¹ = 66564666029 is a prime.

It is a super-2 number, since 2×66564666031² (a number of 22 digits) 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 (66564666037) 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, 3931690 + ... + 3948583.

It is an arithmetic number, because the mean of its divisors is an integer number (16643138688).

Almost surely, 2^66564666031 is an apocalyptic number.

66564666031 is a deficient number, since it is larger than the sum of its proper divisors (7888721).

66564666031 is an equidigital number, since it uses as much as digits as its factorization.

66564666031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7888720.

The product of its (nonzero) digits is 2799360, while the sum is 49.

The spelling of 66564666031 in words is "sixty-six billion, five hundred sixty-four million, six hundred sixty-six thousand, thirty-one".