21786473939472 has 180 divisors, whose sum is σ = 67070406503100. Its totient is φ = 6596864778240.

The previous prime is 21786473939471. The next prime is 21786473939561. The reversal of 21786473939472 is 27493937468712.

21786473939472 is a `hidden beast` number, since 2 + 1 + 7 + 8 + 64 + 7 + 3 + 93 + 9 + 472 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 18719156046096 + 3067317893376 = 4326564^2 + 1751376^2 .

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a self number, because there is not a number n which added to its sum of digits gives 21786473939472.

It is not an unprimeable number, because it can be changed into a prime (21786473939471) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 22116904 + ... + 23080952.

Almost surely, 2^{21786473939472} is an apocalyptic number.

21786473939472 is a gapful number since it is divisible by the number (22) 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 21786473939472, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33535203251550).

21786473939472 is an abundant number, since it is smaller than the sum of its proper divisors (45283932563628).

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

21786473939472 is a wasteful number, since it uses less digits than its factorization.

21786473939472 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 965382 (or 965362 counting only the distinct ones).

The product of its digits is 768144384, while the sum is 72.

The spelling of 21786473939472 in words is "twenty-one trillion, seven hundred eighty-six billion, four hundred seventy-three million, nine hundred thirty-nine thousand, four hundred seventy-two".