643661253325204 has 6 divisors (see below), whose sum is σ = 1126407193319114. Its totient is φ = 321830626662600.

The previous prime is 643661253325147. The next prime is 643661253325229. The reversal of 643661253325204 is 402523352166346.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 540915864729604 + 102745388595600 = 23257598^2 + 10136340^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80457656665647 + ... + 80457656665654.

Almost surely, 2^{643661253325204} is an apocalyptic number.

It is an amenable number.

643661253325204 is a deficient number, since it is larger than the sum of its proper divisors (482745939993910).

643661253325204 is a wasteful number, since it uses less digits than its factorization.

643661253325204 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160915313331305 (or 160915313331303 counting only the distinct ones).

The product of its (nonzero) digits is 18662400, while the sum is 52.

The spelling of 643661253325204 in words is "six hundred forty-three trillion, six hundred sixty-one billion, two hundred fifty-three million, three hundred twenty-five thousand, two hundred four".