644484862762 has 12 divisors (see below), whose sum is σ = 1046811212550. Its totient is φ = 297454551888.

The previous prime is 644484862739. The next prime is 644484862789. The reversal of 644484862762 is 267268484446.

It can be written as a sum of positive squares in 3 ways, for example, as 516398894881 + 128085967881 = 718609^2 + 357891^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 644484862762.

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 in 5 ways as a sum of consecutive naturals, for example, 953379637 + ... + 953380312.

Almost surely, 2^644484862762 is an apocalyptic number.

644484862762 is a deficient number, since it is larger than the sum of its proper divisors (402326349788).

644484862762 is a wasteful number, since it uses less digits than its factorization.

644484862762 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1906759977 (or 1906759964 counting only the distinct ones).

The product of its digits is 99090432, while the sum is 61.

The spelling of 644484862762 in words is "six hundred forty-four billion, four hundred eighty-four million, eight hundred sixty-two thousand, seven hundred sixty-two".