644225516554222 has 4 divisors (see below), whose sum is σ = 966338274831336. Its totient is φ = 322112758277110.

The previous prime is 644225516554219. The next prime is 644225516554247. The reversal of 644225516554222 is 222455615522446.

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

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, 161056379138554 + ... + 161056379138557.

It is an arithmetic number, because the mean of its divisors is an integer number (241584568707834).

Almost surely, 2^{644225516554222} is an apocalyptic number.

644225516554222 is a deficient number, since it is larger than the sum of its proper divisors (322112758277114).

644225516554222 is a wasteful number, since it uses less digits than its factorization.

644225516554222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 322112758277113.

The product of its digits is 46080000, while the sum is 55.

The spelling of 644225516554222 in words is "six hundred forty-four trillion, two hundred twenty-five billion, five hundred sixteen million, five hundred fifty-four thousand, two hundred twenty-two".