678028993 has 4 divisors (see below), whose sum is σ = 699900928. Its totient is φ = 656157060.

The previous prime is 678028987. The next prime is 678029057. The reversal of 678028993 is 399820876.

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 678028993 - 2¹⁷ = 677897921 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 678028993.

It is not an unprimeable number, because it can be changed into a prime (678028963) 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, 10935921 + ... + 10935982.

It is an arithmetic number, because the mean of its divisors is an integer number (174975232).

Almost surely, 2^678028993 is an apocalyptic number.

It is an amenable number.

678028993 is a deficient number, since it is larger than the sum of its proper divisors (21871935).

678028993 is a wasteful number, since it uses less digits than its factorization.

678028993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21871934.

The product of its (nonzero) digits is 1306368, while the sum is 52.

The square root of 678028993 is about 26038.9898613598. The cubic root of 678028993 is about 878.5154865236.

The spelling of 678028993 in words is "six hundred seventy-eight million, twenty-eight thousand, nine hundred ninety-three".