64278993 has 8 divisors (see below), whose sum is σ = 88660800. Its totient is φ = 41374928.

The previous prime is 64278979. The next prime is 64279003. The reversal of 64278993 is 39987246.

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 64278993 - 2⁹ = 64278481 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (64278913) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 369333 + ... + 369506.

It is an arithmetic number, because the mean of its divisors is an integer number (11082600).

Almost surely, 2^64278993 is an apocalyptic number.

It is an amenable number.

64278993 is a deficient number, since it is larger than the sum of its proper divisors (24381807).

64278993 is a wasteful number, since it uses less digits than its factorization.

64278993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 738871.

The product of its digits is 653184, while the sum is 48.

The square root of 64278993 is about 8017.4181006107. The cubic root of 64278993 is about 400.5803928696.

The spelling of 64278993 in words is "sixty-four million, two hundred seventy-eight thousand, nine hundred ninety-three".