6391261 has 2 divisors, whose sum is σ = 6391262. Its totient is φ = 6391260.

The previous prime is 6391247. The next prime is 6391267. The reversal of 6391261 is 1621936.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5428900 + 962361 = 2330^2 + 981^2 .

It is a cyclic number.

It is not a de Polignac number, because 6391261 - 2⁹ = 6390749 is a prime.

It is an Ulam number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6391267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3195630 + 3195631.

It is an arithmetic number, because the mean of its divisors is an integer number (3195631).

Almost surely, 2^6391261 is an apocalyptic number.

It is an amenable number.

6391261 is a deficient number, since it is larger than the sum of its proper divisors (1).

6391261 is an equidigital number, since it uses as much as digits as its factorization.

6391261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1944, while the sum is 28.

The square root of 6391261 is about 2528.0943415941. The cubic root of 6391261 is about 185.5790089252.

It can be divided in two parts, 6391 and 261, that multiplied together give a triangular number (1668051 = T₁₈₂₆).

The spelling of 6391261 in words is "six million, three hundred ninety-one thousand, two hundred sixty-one".