645754331 has 2 divisors, whose sum is σ = 645754332. Its totient is φ = 645754330.

The previous prime is 645754321. The next prime is 645754337. The reversal of 645754331 is 133457546.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 645754331 - 2¹⁴ = 645737947 is a prime.

It is a super-2 number, since 2×645754331² = 833997312010515122, which contains 22 as substring.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (645754337) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322877165 + 322877166.

It is an arithmetic number, because the mean of its divisors is an integer number (322877166).

Almost surely, 2^645754331 is an apocalyptic number.

645754331 is a deficient number, since it is larger than the sum of its proper divisors (1).

645754331 is an equidigital number, since it uses as much as digits as its factorization.

645754331 is an evil number, because the sum of its binary digits is even.

The product of its digits is 151200, while the sum is 38.

The square root of 645754331 is about 25411.6967359521. The cubic root of 645754331 is about 864.3489508933.

The spelling of 645754331 in words is "six hundred forty-five million, seven hundred fifty-four thousand, three hundred thirty-one".