393642820 has 24 divisors (see below), whose sum is σ = 875277144. Its totient is φ = 148194816.

The previous prime is 393642811. The next prime is 393642827. The reversal of 393642820 is 28246393.

It can be written as a sum of positive squares in 4 ways, for example, as 163635264 + 230007556 = 12792^2 + 15166^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 393642820.

It is not an unprimeable number, because it can be changed into a prime (393642827) 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, 578547 + ... + 579226.

It is an arithmetic number, because the mean of its divisors is an integer number (36469881).

Almost surely, 2^393642820 is an apocalyptic number.

It is an amenable number.

393642820 is an abundant number, since it is smaller than the sum of its proper divisors (481634324).

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

393642820 is a wasteful number, since it uses less digits than its factorization.

393642820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1157799 (or 1157797 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 37.

The square root of 393642820 is about 19840.4339670280. The cubic root of 393642820 is about 732.8820947584.

The spelling of 393642820 in words is "three hundred ninety-three million, six hundred forty-two thousand, eight hundred twenty".