64186993 has 4 divisors (see below), whose sum is σ = 69124468. Its totient is φ = 59249520.

The previous prime is 64186981. The next prime is 64187023. The reversal of 64186993 is 39968146.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 39968146 = 2 ⋅19984073.

It can be written as a sum of positive squares in 2 ways, for example, as 38044224 + 26142769 = 6168^2 + 5113^2 .

It is a cyclic number.

It is not a de Polignac number, because 64186993 - 2⁵ = 64186961 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64186963) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2468718 + ... + 2468743.

It is an arithmetic number, because the mean of its divisors is an integer number (17281117).

Almost surely, 2^64186993 is an apocalyptic number.

It is an amenable number.

64186993 is a deficient number, since it is larger than the sum of its proper divisors (4937475).

64186993 is a wasteful number, since it uses less digits than its factorization.

64186993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4937474.

The product of its digits is 279936, while the sum is 46.

The square root of 64186993 is about 8011.6785382340. The cubic root of 64186993 is about 400.3891899551.

The spelling of 64186993 in words is "sixty-four million, one hundred eighty-six thousand, nine hundred ninety-three".