64506391 has 2 divisors, whose sum is σ = 64506392. Its totient is φ = 64506390.

The previous prime is 64506373. The next prime is 64506413. The reversal of 64506391 is 19360546.

64506391 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 64506391 - 2⁵ = 64506359 is a prime.

It is a super-2 number, since 2×64506391² = 8322148959689762, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64506331) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32253195 + 32253196.

It is an arithmetic number, because the mean of its divisors is an integer number (32253196).

Almost surely, 2^64506391 is an apocalyptic number.

64506391 is a deficient number, since it is larger than the sum of its proper divisors (1).

64506391 is an equidigital number, since it uses as much as digits as its factorization.

64506391 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 19440, while the sum is 34.

The square root of 64506391 is about 8031.5870785294. The cubic root of 64506391 is about 401.0522109533.

The spelling of 64506391 in words is "sixty-four million, five hundred six thousand, three hundred ninety-one".