2121751 has 2 divisors, whose sum is σ = 2121752. Its totient is φ = 2121750.

The previous prime is 2121739. The next prime is 2121761. The reversal of 2121751 is 1571212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2121751 - 2⁹ = 2121239 is a prime.

2121751 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2121761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1060875 + 1060876.

It is an arithmetic number, because the mean of its divisors is an integer number (1060876).

2^2121751 is an apocalyptic number.

2121751 is a deficient number, since it is larger than the sum of its proper divisors (1).

2121751 is an equidigital number, since it uses as much as digits as its factorization.

2121751 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 140, while the sum is 19.

The square root of 2121751 is about 1456.6231496169. The cubic root of 2121751 is about 128.4985238063.

Adding to 2121751 its reverse (1571212), we get a palindrome (3692963).

The spelling of 2121751 in words is "two million, one hundred twenty-one thousand, seven hundred fifty-one".