64861433993 has 2 divisors, whose sum is σ = 64861433994. Its totient is φ = 64861433992.

The previous prime is 64861433921. The next prime is 64861433999. The reversal of 64861433993 is 39933416846.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 51142465609 + 13718968384 = 226147^2 + 117128^2 .

It is a cyclic number.

It is not a de Polignac number, because 64861433993 - 2⁸ = 64861433737 is a prime.

It is not a weakly prime, because it can be changed into another prime (64861433999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32430716996 + 32430716997.

It is an arithmetic number, because the mean of its divisors is an integer number (32430716997).

Almost surely, 2^64861433993 is an apocalyptic number.

It is an amenable number.

64861433993 is a deficient number, since it is larger than the sum of its proper divisors (1).

64861433993 is an equidigital number, since it uses as much as digits as its factorization.

64861433993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10077696, while the sum is 56.

The spelling of 64861433993 in words is "sixty-four billion, eight hundred sixty-one million, four hundred thirty-three thousand, nine hundred ninety-three".