21312021102011 has 4 divisors (see below), whose sum is σ = 21312769104432. Its totient is φ = 21311273099592.

The previous prime is 21312021101981. The next prime is 21312021102017. The reversal of 21312021102011 is 11020112021312.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21312021102011 - 2¹⁸ = 21312020839867 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21312021102017) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 373958471 + ... + 374015456.

It is an arithmetic number, because the mean of its divisors is an integer number (5328192276108).

Almost surely, 2^{21312021102011} is an apocalyptic number.

21312021102011 is a deficient number, since it is larger than the sum of its proper divisors (748002421).

21312021102011 is an equidigital number, since it uses as much as digits as its factorization.

21312021102011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 748002420.

The product of its (nonzero) digits is 48, while the sum is 17.

Adding to 21312021102011 its reverse (11020112021312), we get a palindrome (32332133123323).

The spelling of 21312021102011 in words is "twenty-one trillion, three hundred twelve billion, twenty-one million, one hundred two thousand, eleven".