21120241421 has 2 divisors, whose sum is σ = 21120241422. Its totient is φ = 21120241420.

The previous prime is 21120241411. The next prime is 21120241459. The reversal of 21120241421 is 12414202112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21020940196 + 99301225 = 144986^2 + 9965^2 .

It is a cyclic number.

It is not a de Polignac number, because 21120241421 - 2¹⁰ = 21120240397 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21120241393 and 21120241402.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21120241411) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10560120710 + 10560120711.

It is an arithmetic number, because the mean of its divisors is an integer number (10560120711).

Almost surely, 2^21120241421 is an apocalyptic number.

It is an amenable number.

21120241421 is a deficient number, since it is larger than the sum of its proper divisors (1).

21120241421 is an equidigital number, since it uses as much as digits as its factorization.

21120241421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 256, while the sum is 20.

Adding to 21120241421 its reverse (12414202112), we get a palindrome (33534443533).

The spelling of 21120241421 in words is "twenty-one billion, one hundred twenty million, two hundred forty-one thousand, four hundred twenty-one".