21121001011321 has 8 divisors (see below), whose sum is σ = 21432244224744. Its totient is φ = 20810350080000.

The previous prime is 21121001011309. The next prime is 21121001011361. The reversal of 21121001011321 is 12311010012112.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 6997955983225 + 14123045028096 = 2645365^2 + 3758064^2 .

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 21121001011321 - 2³⁵ = 21086641272953 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21121001011295 and 21121001011304.

It is not an unprimeable number, because it can be changed into a prime (21121001011361) 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, 147998680 + ... + 148141321.

It is an arithmetic number, because the mean of its divisors is an integer number (2679030528093).

Almost surely, 2^{21121001011321} is an apocalyptic number.

It is an amenable number.

21121001011321 is a deficient number, since it is larger than the sum of its proper divisors (311243213423).

21121001011321 is an equidigital number, since it uses as much as digits as its factorization.

21121001011321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 296141051.

The product of its (nonzero) digits is 24, while the sum is 16.

Adding to 21121001011321 its reverse (12311010012112), we get a palindrome (33432011023433).

The spelling of 21121001011321 in words is "twenty-one trillion, one hundred twenty-one billion, one million, eleven thousand, three hundred twenty-one".