21381827156660 has 24 divisors (see below), whose sum is σ = 44902673415936. Its totient is φ = 8552571550880.

The previous prime is 21381827156629. The next prime is 21381827156719. The reversal of 21381827156660 is 6665172818312.

21381827156660 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 21381827156596 and 21381827156605.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8853452 + ... + 11006691.

It is an arithmetic number, because the mean of its divisors is an integer number (1870944725664).

Almost surely, 2^{21381827156660} is an apocalyptic number.

21381827156660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21381827156660 is an abundant number, since it is smaller than the sum of its proper divisors (23520846259276).

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

21381827156660 is a wasteful number, since it uses less digits than its factorization.

21381827156660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19913983 (or 19913981 counting only the distinct ones).

The product of its (nonzero) digits is 5806080, while the sum is 56.

The spelling of 21381827156660 in words is "twenty-one trillion, three hundred eighty-one billion, eight hundred twenty-seven million, one hundred fifty-six thousand, six hundred sixty".