645764453 has 4 divisors (see below), whose sum is σ = 645871008. Its totient is φ = 645657900.

The previous prime is 645764429. The next prime is 645764459. The reversal of 645764453 is 354467546.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 645764453 - 2⁶ = 645764389 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645764459) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 43601 + ... + 56502.

It is an arithmetic number, because the mean of its divisors is an integer number (161467752).

Almost surely, 2^645764453 is an apocalyptic number.

It is an amenable number.

645764453 is a deficient number, since it is larger than the sum of its proper divisors (106555).

645764453 is a wasteful number, since it uses less digits than its factorization.

645764453 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106554.

The product of its digits is 1209600, while the sum is 44.

The square root of 645764453 is about 25411.8958954266. The cubic root of 645764453 is about 864.3534670041.

The spelling of 645764453 in words is "six hundred forty-five million, seven hundred sixty-four thousand, four hundred fifty-three".