644554455446 has 12 divisors (see below), whose sum is σ = 1062715817436. Its totient is φ = 292979297820.

The previous prime is 644554455437. The next prime is 644554455469.

644554455446 is nontrivially palindromic in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 644554455391 and 644554455400.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1331723840 + ... + 1331724323.

It is an arithmetic number, because the mean of its divisors is an integer number (88559651453).

Almost surely, 2^644554455446 is an apocalyptic number.

644554455446 is a deficient number, since it is larger than the sum of its proper divisors (418161361990).

644554455446 is a wasteful number, since it uses less digits than its factorization.

644554455446 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2663448187 (or 2663448176 counting only the distinct ones).

The product of its digits is 92160000, while the sum is 56.

The spelling of 644554455446 in words is "six hundred forty-four billion, five hundred fifty-four million, four hundred fifty-five thousand, four hundred forty-six".