18018001656 has 96 divisors (see below), whose sum is σ = 49474545120. Its totient is φ = 5923296000.

The previous prime is 18018001643. The next prime is 18018001679. The reversal of 18018001656 is 65610081081.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 18018001656.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1907826 + ... + 1917246.

It is an arithmetic number, because the mean of its divisors is an integer number (515359845).

Almost surely, 2^18018001656 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18018001656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24737272560).

18018001656 is an abundant number, since it is smaller than the sum of its proper divisors (31456543464).

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

18018001656 is a wasteful number, since it uses less digits than its factorization.

18018001656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9797 (or 9790 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 36.

The spelling of 18018001656 in words is "eighteen billion, eighteen million, one thousand, six hundred fifty-six".