6404129491 has 2 divisors, whose sum is σ = 6404129492. Its totient is φ = 6404129490.

The previous prime is 6404129447. The next prime is 6404129503. The reversal of 6404129491 is 1949214046.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6404129491 is a prime.

It is not a weakly prime, because it can be changed into another prime (6404129401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3202064745 + 3202064746.

It is an arithmetic number, because the mean of its divisors is an integer number (3202064746).

Almost surely, 2^6404129491 is an apocalyptic number.

6404129491 is a deficient number, since it is larger than the sum of its proper divisors (1).

6404129491 is an equidigital number, since it uses as much as digits as its factorization.

6404129491 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 62208, while the sum is 40.

The square root of 6404129491 is about 80025.8051568368. The cubic root of 6404129491 is about 1857.0347684099.

The spelling of 6404129491 in words is "six billion, four hundred four million, one hundred twenty-nine thousand, four hundred ninety-one".