64637993 has 8 divisors (see below), whose sum is σ = 74762688. Its totient is φ = 54735984.

The previous prime is 64637977. The next prime is 64638031. The reversal of 64637993 is 39973646.

64637993 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 64637993 - 2⁴ = 64637977 is a prime.

It is a super-3 number, since 3×64637993³ (a number of 24 digits) contains 333 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (64637693) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 55046 + ... + 56207.

It is an arithmetic number, because the mean of its divisors is an integer number (9345336).

Almost surely, 2^64637993 is an apocalyptic number.

It is an amenable number.

64637993 is a deficient number, since it is larger than the sum of its proper divisors (10124695).

64637993 is a wasteful number, since it uses less digits than its factorization.

64637993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111343.

The product of its digits is 734832, while the sum is 47.

The square root of 64637993 is about 8039.7756809503. The cubic root of 64637993 is about 401.3247597686.

The spelling of 64637993 in words is "sixty-four million, six hundred thirty-seven thousand, nine hundred ninety-three".