393138367818 has 128 divisors (see below), whose sum is σ = 935144663040. Its totient is φ = 107805600000.

The previous prime is 393138367793. The next prime is 393138367819. The reversal of 393138367818 is 818763831393.

It is a super-2 number, since 2×393138367818² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (393138367819) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 211250208 + ... + 211252068.

It is an arithmetic number, because the mean of its divisors is an integer number (7305817680).

Almost surely, 2^393138367818 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 393138367818, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (467572331520).

393138367818 is an abundant number, since it is smaller than the sum of its proper divisors (542006295222).

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

393138367818 is a wasteful number, since it uses less digits than its factorization.

393138367818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2844.

The product of its digits is 15676416, while the sum is 60.

The spelling of 393138367818 in words is "three hundred ninety-three billion, one hundred thirty-eight million, three hundred sixty-seven thousand, eight hundred eighteen".