6406191257 has 2 divisors, whose sum is σ = 6406191258. Its totient is φ = 6406191256.

The previous prime is 6406191223. The next prime is 6406191283. The reversal of 6406191257 is 7521916046.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5652633856 + 753557401 = 75184^2 + 27451^2 .

It is a cyclic number.

It is not a de Polignac number, because 6406191257 - 2¹⁸ = 6405929113 is a prime.

It is not a weakly prime, because it can be changed into another prime (6406191457) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3203095628 + 3203095629.

It is an arithmetic number, because the mean of its divisors is an integer number (3203095629).

Almost surely, 2^6406191257 is an apocalyptic number.

It is an amenable number.

6406191257 is a deficient number, since it is larger than the sum of its proper divisors (1).

6406191257 is an equidigital number, since it uses as much as digits as its factorization.

6406191257 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 90720, while the sum is 41.

The square root of 6406191257 is about 80038.6860024576. The cubic root of 6406191257 is about 1857.2340336050.

The spelling of 6406191257 in words is "six billion, four hundred six million, one hundred ninety-one thousand, two hundred fifty-seven".