645135983 has 2 divisors, whose sum is σ = 645135984. Its totient is φ = 645135982.

The previous prime is 645135979. The next prime is 645136021. The reversal of 645135983 is 389531546.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 645135983 - 2² = 645135979 is a prime.

It is a super-2 number, since 2×645135983² = 832400873122752578, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (645135083) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322567991 + 322567992.

It is an arithmetic number, because the mean of its divisors is an integer number (322567992).

Almost surely, 2^645135983 is an apocalyptic number.

645135983 is a deficient number, since it is larger than the sum of its proper divisors (1).

645135983 is an equidigital number, since it uses as much as digits as its factorization.

645135983 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 388800, while the sum is 44.

The square root of 645135983 is about 25399.5272200094. The cubic root of 645135983 is about 864.0729743569.

The spelling of 645135983 in words is "six hundred forty-five million, one hundred thirty-five thousand, nine hundred eighty-three".