646441379 has 2 divisors, whose sum is σ = 646441380. Its totient is φ = 646441378.

The previous prime is 646441363. The next prime is 646441391. The reversal of 646441379 is 973144646.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 646441379 - 2⁴ = 646441363 is a prime.

It is equal to p_33617996 and since 646441379 and 33617996 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 (646441079) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323220689 + 323220690.

It is an arithmetic number, because the mean of its divisors is an integer number (323220690).

Almost surely, 2^646441379 is an apocalyptic number.

646441379 is a deficient number, since it is larger than the sum of its proper divisors (1).

646441379 is an equidigital number, since it uses as much as digits as its factorization.

646441379 is an evil number, because the sum of its binary digits is even.

The product of its digits is 435456, while the sum is 44.

The square root of 646441379 is about 25425.2114838795. The cubic root of 646441379 is about 864.6553825635.

The spelling of 646441379 in words is "six hundred forty-six million, four hundred forty-one thousand, three hundred seventy-nine".