644416411 has 2 divisors, whose sum is σ = 644416412. Its totient is φ = 644416410.

The previous prime is 644416397. The next prime is 644416429. The reversal of 644416411 is 114614446.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 644416411 - 2¹¹ = 644414363 is a prime.

It is a super-2 number, since 2×644416411² = 830545021532241842, which contains 22 as substring.

It is equal to p_33518056 and since 644416411 and 33518056 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (644416111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322208205 + 322208206.

It is an arithmetic number, because the mean of its divisors is an integer number (322208206).

Almost surely, 2^644416411 is an apocalyptic number.

644416411 is a deficient number, since it is larger than the sum of its proper divisors (1).

644416411 is an equidigital number, since it uses as much as digits as its factorization.

644416411 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9216, while the sum is 31.

The square root of 644416411 is about 25385.3582011363. The cubic root of 644416411 is about 863.7515981688.

The spelling of 644416411 in words is "six hundred forty-four million, four hundred sixteen thousand, four hundred eleven".