2113120021 has 2 divisors, whose sum is σ = 2113120022. Its totient is φ = 2113120020.

The previous prime is 2113120007. The next prime is 2113120039. The reversal of 2113120021 is 1200213112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1500012900 + 613107121 = 38730^2 + 24761^2 .

It is a cyclic number.

It is not a de Polignac number, because 2113120021 - 2⁷ = 2113119893 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2113119983 and 2113120010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2113120721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1056560010 + 1056560011.

It is an arithmetic number, because the mean of its divisors is an integer number (1056560011).

Almost surely, 2^2113120021 is an apocalyptic number.

It is an amenable number.

2113120021 is a deficient number, since it is larger than the sum of its proper divisors (1).

2113120021 is an equidigital number, since it uses as much as digits as its factorization.

2113120021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 2113120021 is about 45968.6852215723. The cubic root of 2113120021 is about 1283.2404915276.

Adding to 2113120021 its reverse (1200213112), we get a palindrome (3313333133).

The spelling of 2113120021 in words is "two billion, one hundred thirteen million, one hundred twenty thousand, twenty-one".