644424263246 has 4 divisors (see below), whose sum is σ = 966636394872. Its totient is φ = 322212131622.

The previous prime is 644424263233. The next prime is 644424263257. The reversal of 644424263246 is 642362424446.

644424263246 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a self number, because there is not a number n which added to its sum of digits gives 644424263246.

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, 161106065810 + ... + 161106065813.

It is an arithmetic number, because the mean of its divisors is an integer number (241659098718).

Almost surely, 2^644424263246 is an apocalyptic number.

644424263246 is a deficient number, since it is larger than the sum of its proper divisors (322212131626).

644424263246 is a wasteful number, since it uses less digits than its factorization.

644424263246 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 322212131625.

The product of its digits is 5308416, while the sum is 47.

The spelling of 644424263246 in words is "six hundred forty-four billion, four hundred twenty-four million, two hundred sixty-three thousand, two hundred forty-six".