18216393426 has 288 divisors, whose sum is σ = 51866006400. Its totient is φ = 4699775520.

The previous prime is 18216393421. The next prime is 18216393443. The reversal of 18216393426 is 62439361281.

18216393426 is a `hidden beast` number, since 1 + 8 + 2 + 1 + 639 + 3 + 4 + 2 + 6 = 666.

It is not an unprimeable number, because it can be changed into a prime (18216393421) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 122257600 + ... + 122257748.

It is an arithmetic number, because the mean of its divisors is an integer number (180090300).

Almost surely, 2^18216393426 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18216393426, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25933003200).

18216393426 is an abundant number, since it is smaller than the sum of its proper divisors (33649612974).

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

18216393426 is an frugal number, since it uses more digits than its factorization.

18216393426 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 215 (or 172 counting only the distinct ones).

The product of its digits is 373248, while the sum is 45.

The spelling of 18216393426 in words is "eighteen billion, two hundred sixteen million, three hundred ninety-three thousand, four hundred twenty-six".