645243635 has 8 divisors (see below), whose sum is σ = 776091456. Its totient is φ = 514995520.

The previous prime is 645243631. The next prime is 645243661. The reversal of 645243635 is 536342546.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 645243635 - 2² = 645243631 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645243631) 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 7 ways as a sum of consecutive naturals, for example, 147554 + ... + 151863.

It is an arithmetic number, because the mean of its divisors is an integer number (97011432).

Almost surely, 2^645243635 is an apocalyptic number.

645243635 is a deficient number, since it is larger than the sum of its proper divisors (130847821).

645243635 is a wasteful number, since it uses less digits than its factorization.

645243635 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 299853.

The product of its digits is 259200, while the sum is 38.

The square root of 645243635 is about 25401.6463049150. The cubic root of 645243635 is about 864.1210334808.

The spelling of 645243635 in words is "six hundred forty-five million, two hundred forty-three thousand, six hundred thirty-five".