665623031 has 2 divisors, whose sum is σ = 665623032. Its totient is φ = 665623030.

The previous prime is 665623003. The next prime is 665623097. The reversal of 665623031 is 130326566.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-665623031 is a prime.

It is a super-2 number, since 2×665623031² = 886108038795253922, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (665623001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332811515 + 332811516.

It is an arithmetic number, because the mean of its divisors is an integer number (332811516).

Almost surely, 2^665623031 is an apocalyptic number.

665623031 is a deficient number, since it is larger than the sum of its proper divisors (1).

665623031 is an equidigital number, since it uses as much as digits as its factorization.

665623031 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 19440, while the sum is 32.

The square root of 665623031 is about 25799.6711413150. The cubic root of 665623031 is about 873.1243767933.

Adding to 665623031 its reverse (130326566), we get a palindrome (795949597).

The spelling of 665623031 in words is "six hundred sixty-five million, six hundred twenty-three thousand, thirty-one".