393042978 has 12 divisors (see below), whose sum is σ = 851593158. Its totient is φ = 131014320.

The previous prime is 393042973. The next prime is 393042983. The reversal of 393042978 is 879240393.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (393042973) and next prime (393042983).

It can be written as a sum of positive squares in only one way, i.e., 340291809 + 52751169 = 18447^2 + 7263^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (393042973) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 10917843 + ... + 10917878.

Almost surely, 2^393042978 is an apocalyptic number.

393042978 is an abundant number, since it is smaller than the sum of its proper divisors (458550180).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

393042978 is a wasteful number, since it uses less digits than its factorization.

393042978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21835729 (or 21835726 counting only the distinct ones).

The product of its (nonzero) digits is 326592, while the sum is 45.

The square root of 393042978 is about 19825.3115486239. The cubic root of 393042978 is about 732.5096446369.

The spelling of 393042978 in words is "three hundred ninety-three million, forty-two thousand, nine hundred seventy-eight".