18121633464 has 64 divisors (see below), whose sum is σ = 49549968000. Its totient is φ = 5477256320.

The previous prime is 18121633433. The next prime is 18121633511. The reversal of 18121633464 is 46433612181.

It is a happy number.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14467 + ... + 190925.

It is an arithmetic number, because the mean of its divisors is an integer number (774218250).

Almost surely, 2^18121633464 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 18121633464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24774984000).

18121633464 is an abundant number, since it is smaller than the sum of its proper divisors (31428334536).

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

18121633464 is a wasteful number, since it uses less digits than its factorization.

18121633464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 176868 (or 176864 counting only the distinct ones).

The product of its digits is 82944, while the sum is 39.

The spelling of 18121633464 in words is "eighteen billion, one hundred twenty-one million, six hundred thirty-three thousand, four hundred sixty-four".