2121761 has 2 divisors, whose sum is σ = 2121762. Its totient is φ = 2121760.

The previous prime is 2121751. The next prime is 2121767. The reversal of 2121761 is 1671212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1345600 + 776161 = 1160^2 + 881^2 .

It is a cyclic number.

It is not a de Polignac number, because 2121761 - 2¹⁴ = 2105377 is a prime.

It is a super-2 number, since 2×2121761² = 9003739482242, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (2121767) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1060880 + 1060881.

It is an arithmetic number, because the mean of its divisors is an integer number (1060881).

2^2121761 is an apocalyptic number.

It is an amenable number.

2121761 is a deficient number, since it is larger than the sum of its proper divisors (1).

2121761 is an equidigital number, since it uses as much as digits as its factorization.

2121761 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 168, while the sum is 20.

The square root of 2121761 is about 1456.6265822097. The cubic root of 2121761 is about 128.4987256809.

Adding to 2121761 its reverse (1671212), we get a palindrome (3792973).

It can be divided in two parts, 2121 and 761, that added together give a palindrome (2882).

The spelling of 2121761 in words is "two million, one hundred twenty-one thousand, seven hundred sixty-one".