21284533178612 has 72 divisors (see below), whose sum is σ = 43960012417440. Its totient is φ = 8917869363840.

The previous prime is 21284533178569. The next prime is 21284533178617. The reversal of 21284533178612 is 21687133548212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21284533178617) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8154263 + ... + 10443230.

It is an arithmetic number, because the mean of its divisors is an integer number (610555728020).

Almost surely, 2^{21284533178612} is an apocalyptic number.

21284533178612 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21284533178612 is an abundant number, since it is smaller than the sum of its proper divisors (22675479238828).

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

21284533178612 is a wasteful number, since it uses less digits than its factorization.

21284533178612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18597601 (or 18597562 counting only the distinct ones).

The product of its digits is 3870720, while the sum is 53.

The spelling of 21284533178612 in words is "twenty-one trillion, two hundred eighty-four billion, five hundred thirty-three million, one hundred seventy-eight thousand, six hundred twelve".