393942878 has 8 divisors (see below), whose sum is σ = 675330672. Its totient is φ = 168832656.

The previous prime is 393942877. The next prime is 393942889. The reversal of 393942878 is 878249393.

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

It is a super-2 number, since 2×393942878² = 310381982253845768, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (393942877) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14069375 + ... + 14069402.

It is an arithmetic number, because the mean of its divisors is an integer number (84416334).

Almost surely, 2^393942878 is an apocalyptic number.

393942878 is a deficient number, since it is larger than the sum of its proper divisors (281387794).

393942878 is a wasteful number, since it uses less digits than its factorization.

393942878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28138786.

The product of its digits is 2612736, while the sum is 53.

The square root of 393942878 is about 19847.9943067303. The cubic root of 393942878 is about 733.0682629229.

The spelling of 393942878 in words is "three hundred ninety-three million, nine hundred forty-two thousand, eight hundred seventy-eight".