21756353213 has 8 divisors (see below), whose sum is σ = 24891824832. Its totient is φ = 18627736896.

The previous prime is 21756353183. The next prime is 21756353219. The reversal of 21756353213 is 31235365712.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21756353213 - 2¹⁴ = 21756336829 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21756353219) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1707020 + ... + 1719717.

It is an arithmetic number, because the mean of its divisors is an integer number (3111478104).

Almost surely, 2^21756353213 is an apocalyptic number.

It is an amenable number.

21756353213 is a deficient number, since it is larger than the sum of its proper divisors (3135471619).

21756353213 is an equidigital number, since it uses as much as digits as its factorization.

21756353213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3427651.

The product of its digits is 113400, while the sum is 38.

The spelling of 21756353213 in words is "twenty-one billion, seven hundred fifty-six million, three hundred fifty-three thousand, two hundred thirteen".