641787449 has 2 divisors, whose sum is σ = 641787450. Its totient is φ = 641787448.

The previous prime is 641787437. The next prime is 641787467. The reversal of 641787449 is 944787146.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 336062224 + 305725225 = 18332^2 + 17485^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-641787449 is a prime.

It is a super-2 number, since 2×641787449² = 823782259387855202, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 641787397 and 641787406.

It is not a weakly prime, because it can be changed into another prime (641787479) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320893724 + 320893725.

It is an arithmetic number, because the mean of its divisors is an integer number (320893725).

Almost surely, 2^641787449 is an apocalyptic number.

It is an amenable number.

641787449 is a deficient number, since it is larger than the sum of its proper divisors (1).

641787449 is an equidigital number, since it uses as much as digits as its factorization.

641787449 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1354752, while the sum is 50.

The square root of 641787449 is about 25333.5242120002. The cubic root of 641787449 is about 862.5754098877.

The spelling of 641787449 in words is "six hundred forty-one million, seven hundred eighty-seven thousand, four hundred forty-nine".