18664215478272 has 1496 divisors, whose sum is σ = 70213358978784. Its totient is φ = 4829554409472.

The previous prime is 18664215478241. The next prime is 18664215478313. The reversal of 18664215478272 is 27287451246681.

18664215478272 is a `hidden beast` number, since 1 + 8 + 6 + 6 + 4 + 2 + 1 + 547 + 82 + 7 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 87 ways as a sum of consecutive naturals, for example, 352155008998 + ... + 352155009050.

Almost surely, 2^{18664215478272} is an apocalyptic number.

18664215478272 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18664215478272, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35106679489392).

18664215478272 is an abundant number, since it is smaller than the sum of its proper divisors (51549143500512).

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

18664215478272 is an frugal number, since it uses more digits than its factorization.

18664215478272 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135 (or 78 counting only the distinct ones).

The product of its digits is 72253440, while the sum is 63.

The spelling of 18664215478272 in words is "eighteen trillion, six hundred sixty-four billion, two hundred fifteen million, four hundred seventy-eight thousand, two hundred seventy-two".