6405662491 has 2 divisors, whose sum is σ = 6405662492. Its totient is φ = 6405662490.

The previous prime is 6405662447. The next prime is 6405662503. The reversal of 6405662491 is 1942665046.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 6405662491 - 2²¹ = 6403565339 is a prime.

It is not a weakly prime, because it can be changed into another prime (6405662411) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3202831245 + 3202831246.

It is an arithmetic number, because the mean of its divisors is an integer number (3202831246).

Almost surely, 2^6405662491 is an apocalyptic number.

6405662491 is a deficient number, since it is larger than the sum of its proper divisors (1).

6405662491 is an equidigital number, since it uses as much as digits as its factorization.

6405662491 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 311040, while the sum is 43.

The square root of 6405662491 is about 80035.3827441339. The cubic root of 6405662491 is about 1857.1829335992.

The spelling of 6405662491 in words is "six billion, four hundred five million, six hundred sixty-two thousand, four hundred ninety-one".