64043645437 has 4 divisors (see below), whose sum is σ = 67810918716. Its totient is φ = 60276372160.

The previous prime is 64043645431. The next prime is 64043645509. The reversal of 64043645437 is 73454634046.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 52081629796 + 11962015641 = 228214^2 + 109371^2 .

It is a cyclic number.

It is not a de Polignac number, because 64043645437 - 2¹⁵ = 64043612669 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 (64043645431) 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, 1883636614 + ... + 1883636647.

It is an arithmetic number, because the mean of its divisors is an integer number (16952729679).

Almost surely, 2^64043645437 is an apocalyptic number.

It is an amenable number.

64043645437 is a deficient number, since it is larger than the sum of its proper divisors (3767273279).

64043645437 is a wasteful number, since it uses less digits than its factorization.

64043645437 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3767273278.

The product of its (nonzero) digits is 2903040, while the sum is 46.

The spelling of 64043645437 in words is "sixty-four billion, forty-three million, six hundred forty-five thousand, four hundred thirty-seven".