2111511421 has 2 divisors, whose sum is σ = 2111511422. Its totient is φ = 2111511420.

The previous prime is 2111511397. The next prime is 2111511443. The reversal of 2111511421 is 1241151112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1850204196 + 261307225 = 43014^2 + 16165^2 .

It is a cyclic number.

It is not a de Polignac number, because 2111511421 - 2¹⁵ = 2111478653 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2111511491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1055755710 + 1055755711.

It is an arithmetic number, because the mean of its divisors is an integer number (1055755711).

Almost surely, 2^2111511421 is an apocalyptic number.

It is an amenable number.

2111511421 is a deficient number, since it is larger than the sum of its proper divisors (1).

2111511421 is an equidigital number, since it uses as much as digits as its factorization.

2111511421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 80, while the sum is 19.

The square root of 2111511421 is about 45951.1851969022. The cubic root of 2111511421 is about 1282.9147891464.

Adding to 2111511421 its reverse (1241151112), we get a palindrome (3352662533).

The spelling of 2111511421 in words is "two billion, one hundred eleven million, five hundred eleven thousand, four hundred twenty-one".