64638188533 has 4 divisors (see below), whose sum is σ = 64709455360. Its totient is φ = 64566921708.

The previous prime is 64638188467. The next prime is 64638188543. The reversal of 64638188533 is 33588183646.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 64638188533 - 2³³ = 56048253941 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64638188543) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 35632053 + ... + 35633866.

It is an arithmetic number, because the mean of its divisors is an integer number (16177363840).

Almost surely, 2^64638188533 is an apocalyptic number.

It is an amenable number.

64638188533 is a deficient number, since it is larger than the sum of its proper divisors (71266827).

64638188533 is an equidigital number, since it uses as much as digits as its factorization.

64638188533 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71266826.

The product of its digits is 9953280, while the sum is 55.

The spelling of 64638188533 in words is "sixty-four billion, six hundred thirty-eight million, one hundred eighty-eight thousand, five hundred thirty-three".