645030761 has 2 divisors, whose sum is σ = 645030762. Its totient is φ = 645030760.

The previous prime is 645030707. The next prime is 645030767. The reversal of 645030761 is 167030546.

645030761 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 611622361 + 33408400 = 24731^2 + 5780^2 .

It is a cyclic number.

It is not a de Polignac number, because 645030761 - 2²² = 640836457 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (645030767) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322515380 + 322515381.

It is an arithmetic number, because the mean of its divisors is an integer number (322515381).

Almost surely, 2^645030761 is an apocalyptic number.

It is an amenable number.

645030761 is a deficient number, since it is larger than the sum of its proper divisors (1).

645030761 is an equidigital number, since it uses as much as digits as its factorization.

645030761 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15120, while the sum is 32.

The square root of 645030761 is about 25397.4557977763. The cubic root of 645030761 is about 864.0259948919.

The spelling of 645030761 in words is "six hundred forty-five million, thirty thousand, seven hundred sixty-one".