66443831 has 2 divisors, whose sum is σ = 66443832. Its totient is φ = 66443830.

The previous prime is 66443827. The next prime is 66443857. The reversal of 66443831 is 13834466.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66443831 - 2² = 66443827 is a prime.

It is a super-2 number, since 2×66443831² = 8829565355913122, which contains 22 as substring.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 66443791 and 66443800.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66443801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33221915 + 33221916.

It is an arithmetic number, because the mean of its divisors is an integer number (33221916).

Almost surely, 2^66443831 is an apocalyptic number.

66443831 is a deficient number, since it is larger than the sum of its proper divisors (1).

66443831 is an equidigital number, since it uses as much as digits as its factorization.

66443831 is an evil number, because the sum of its binary digits is even.

The product of its digits is 41472, while the sum is 35.

The square root of 66443831 is about 8151.3085452582. The cubic root of 66443831 is about 405.0278515622.

The spelling of 66443831 in words is "sixty-six million, four hundred forty-three thousand, eight hundred thirty-one".