644030477 has 2 divisors, whose sum is σ = 644030478. Its totient is φ = 644030476.

The previous prime is 644030437. The next prime is 644030557. The reversal of 644030477 is 774030446.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 634082761 + 9947716 = 25181^2 + 3154^2 .

It is a cyclic number.

It is not a de Polignac number, because 644030477 - 2¹⁴ = 644014093 is a prime.

It is a super-3 number, since 3×644030477³ (a number of 27 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (644030437) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322015238 + 322015239.

It is an arithmetic number, because the mean of its divisors is an integer number (322015239).

Almost surely, 2^644030477 is an apocalyptic number.

It is an amenable number.

644030477 is a deficient number, since it is larger than the sum of its proper divisors (1).

644030477 is an equidigital number, since it uses as much as digits as its factorization.

644030477 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 56448, while the sum is 35.

The square root of 644030477 is about 25377.7555548161. The cubic root of 644030477 is about 863.5791332468.

The spelling of 644030477 in words is "six hundred forty-four million, thirty thousand, four hundred seventy-seven".