1964438591 has 2 divisors, whose sum is σ = 1964438592. Its totient is φ = 1964438590.

The previous prime is 1964438563. The next prime is 1964438599. The reversal of 1964438591 is 1958344691.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1964438591 - 2²² = 1960244287 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1964438599) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 982219295 + 982219296.

It is an arithmetic number, because the mean of its divisors is an integer number (982219296).

Almost surely, 2^1964438591 is an apocalyptic number.

1964438591 is a deficient number, since it is larger than the sum of its proper divisors (1).

1964438591 is an equidigital number, since it uses as much as digits as its factorization.

1964438591 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 933120, while the sum is 50.

The square root of 1964438591 is about 44321.9876697785. The cubic root of 1964438591 is about 1252.4089207784.

The spelling of 1964438591 in words is "one billion, nine hundred sixty-four million, four hundred thirty-eight thousand, five hundred ninety-one".