2124040021 has 2 divisors, whose sum is σ = 2124040022. Its totient is φ = 2124040020.

The previous prime is 2124040007. The next prime is 2124040033. The reversal of 2124040021 is 1200404212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1157700625 + 966339396 = 34025^2 + 31086^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2124040021 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2124039977 and 2124040004.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2124040081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1062020010 + 1062020011.

It is an arithmetic number, because the mean of its divisors is an integer number (1062020011).

Almost surely, 2^2124040021 is an apocalyptic number.

It is an amenable number.

2124040021 is a deficient number, since it is larger than the sum of its proper divisors (1).

2124040021 is an equidigital number, since it uses as much as digits as its factorization.

2124040021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 2124040021 is about 46087.3086760336. The cubic root of 2124040021 is about 1285.4471680253.

Adding to 2124040021 its reverse (1200404212), we get a palindrome (3324444233).

The spelling of 2124040021 in words is "two billion, one hundred twenty-four million, forty thousand, twenty-one".