645769451 has 2 divisors, whose sum is σ = 645769452. Its totient is φ = 645769450.

The previous prime is 645769441. The next prime is 645769499. The reversal of 645769451 is 154967546.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 645769451 - 2¹⁴ = 645753067 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 645769396 and 645769405.

It is not a weakly prime, because it can be changed into another prime (645769441) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322884725 + 322884726.

It is an arithmetic number, because the mean of its divisors is an integer number (322884726).

Almost surely, 2^645769451 is an apocalyptic number.

645769451 is a deficient number, since it is larger than the sum of its proper divisors (1).

645769451 is an equidigital number, since it uses as much as digits as its factorization.

645769451 is an evil number, because the sum of its binary digits is even.

The product of its digits is 907200, while the sum is 47.

The square root of 645769451 is about 25411.9942350064. The cubic root of 645769451 is about 864.3556969336.

The spelling of 645769451 in words is "six hundred forty-five million, seven hundred sixty-nine thousand, four hundred fifty-one".