645304135006642 has 4 divisors (see below), whose sum is σ = 967956202509966. Its totient is φ = 322652067503320.

The previous prime is 645304135006561. The next prime is 645304135006691. The reversal of 645304135006642 is 246600531403546.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 517609411562961 + 127694723443681 = 22751031^2 + 11300209^2 .

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 161326033751659 + ... + 161326033751662.

Almost surely, 2^{645304135006642} is an apocalyptic number.

645304135006642 is a deficient number, since it is larger than the sum of its proper divisors (322652067503324).

645304135006642 is a wasteful number, since it uses less digits than its factorization.

645304135006642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 322652067503323.

The product of its (nonzero) digits is 6220800, while the sum is 49.

The spelling of 645304135006642 in words is "six hundred forty-five trillion, three hundred four billion, one hundred thirty-five million, six thousand, six hundred forty-two".