21356253751660 has 48 divisors (see below), whose sum is σ = 44867953620000. Its totient is φ = 8538726933504.

The previous prime is 21356253751549. The next prime is 21356253751661. The reversal of 21356253751660 is 6615735265312.

It is a junction number, because it is equal to n+sod(n) for n = 21356253751598 and 21356253751607.

It is not an unprimeable number, because it can be changed into a prime (21356253751661) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 540658591 + ... + 540698089.

It is an arithmetic number, because the mean of its divisors is an integer number (934749033750).

Almost surely, 2^{21356253751660} is an apocalyptic number.

21356253751660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21356253751660 is an abundant number, since it is smaller than the sum of its proper divisors (23511699868340).

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

21356253751660 is a wasteful number, since it uses less digits than its factorization.

21356253751660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50770 (or 50768 counting only the distinct ones).

The product of its (nonzero) digits is 6804000, while the sum is 52.

The spelling of 21356253751660 in words is "twenty-one trillion, three hundred fifty-six billion, two hundred fifty-three million, seven hundred fifty-one thousand, six hundred sixty".