64191943 has 2 divisors, whose sum is σ = 64191944. Its totient is φ = 64191942.

The previous prime is 64191931. The next prime is 64191971. The reversal of 64191943 is 34919146.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 64191943 - 2⁹ = 64191431 is a prime.

It is a super-2 number, since 2×64191943² = 8241211092230498, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64191913) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32095971 + 32095972.

It is an arithmetic number, because the mean of its divisors is an integer number (32095972).

Almost surely, 2^64191943 is an apocalyptic number.

64191943 is a deficient number, since it is larger than the sum of its proper divisors (1).

64191943 is an equidigital number, since it uses as much as digits as its factorization.

64191943 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23328, while the sum is 37.

The square root of 64191943 is about 8011.9874563057. The cubic root of 64191943 is about 400.3994821522.

The spelling of 64191943 in words is "sixty-four million, one hundred ninety-one thousand, nine hundred forty-three".