6432991 has 2 divisors, whose sum is σ = 6432992. Its totient is φ = 6432990.

The previous prime is 6432989. The next prime is 6433003. The reversal of 6432991 is 1992346.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 6432991 - 2¹ = 6432989 is a prime.

Together with 6432989, it forms a pair of twin primes.

It is a nialpdrome in base 15.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6432901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3216495 + 3216496.

It is an arithmetic number, because the mean of its divisors is an integer number (3216496).

Almost surely, 2^6432991 is an apocalyptic number.

6432991 is a deficient number, since it is larger than the sum of its proper divisors (1).

6432991 is an equidigital number, since it uses as much as digits as its factorization.

6432991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11664, while the sum is 34.

The square root of 6432991 is about 2536.3341656809. The cubic root of 6432991 is about 185.9820289416.

The spelling of 6432991 in words is "six million, four hundred thirty-two thousand, nine hundred ninety-one".