644466047 has 2 divisors, whose sum is σ = 644466048. Its totient is φ = 644466046.

The previous prime is 644466041. The next prime is 644466079. The reversal of 644466047 is 740664446.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 644466047 - 2¹⁶ = 644400511 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 644465995 and 644466013.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (644466041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322233023 + 322233024.

It is an arithmetic number, because the mean of its divisors is an integer number (322233024).

Almost surely, 2^644466047 is an apocalyptic number.

644466047 is a deficient number, since it is larger than the sum of its proper divisors (1).

644466047 is an equidigital number, since it uses as much as digits as its factorization.

644466047 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 387072, while the sum is 41.

The square root of 644466047 is about 25386.3358324907. The cubic root of 644466047 is about 863.7737743440.

The spelling of 644466047 in words is "six hundred forty-four million, four hundred sixty-six thousand, forty-seven".