644225048977 has 8 divisors (see below), whose sum is σ = 648428007656. Its totient is φ = 640023351552.

The previous prime is 644225048953. The next prime is 644225048981. The reversal of 644225048977 is 779840522446.

It can be written as a sum of positive squares in 4 ways, for example, as 358081363201 + 286143685776 = 598399^2 + 534924^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 644225048977 - 2¹⁵ = 644225016209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (644225048927) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 720643 + ... + 1344535.

It is an arithmetic number, because the mean of its divisors is an integer number (81053500957).

Almost surely, 2^644225048977 is an apocalyptic number.

It is an amenable number.

644225048977 is a deficient number, since it is larger than the sum of its proper divisors (4202958679).

644225048977 is a wasteful number, since it uses less digits than its factorization.

644225048977 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 630627.

The product of its (nonzero) digits is 27095040, while the sum is 58.

The spelling of 644225048977 in words is "six hundred forty-four billion, two hundred twenty-five million, forty-eight thousand, nine hundred seventy-seven".