644734669954 has 4 divisors (see below), whose sum is σ = 967102004934. Its totient is φ = 322367334976.

The previous prime is 644734669921. The next prime is 644734669967. The reversal of 644734669954 is 459966437446.

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., 365922157225 + 278812512729 = 604915^2 + 528027^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 644734669954.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 161183667487 + ... + 161183667490.

Almost surely, 2^644734669954 is an apocalyptic number.

644734669954 is a deficient number, since it is larger than the sum of its proper divisors (322367334980).

644734669954 is a wasteful number, since it uses less digits than its factorization.

644734669954 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 322367334979.

The product of its digits is 470292480, while the sum is 67.

The spelling of 644734669954 in words is "six hundred forty-four billion, seven hundred thirty-four million, six hundred sixty-nine thousand, nine hundred fifty-four".