7122121 has 2 divisors, whose sum is σ = 7122122. Its totient is φ = 7122120.

The previous prime is 7122119. The next prime is 7122149. The reversal of 7122121 is 1212217.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6375625 + 746496 = 2525^2 + 864^2 .

It is a cyclic number.

It is not a de Polignac number, because 7122121 - 2¹ = 7122119 is a prime.

Together with 7122119, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 7122095 and 7122104.

It is not a weakly prime, because it can be changed into another prime (7122721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3561060 + 3561061.

It is an arithmetic number, because the mean of its divisors is an integer number (3561061).

Almost surely, 2^7122121 is an apocalyptic number.

It is an amenable number.

7122121 is a deficient number, since it is larger than the sum of its proper divisors (1).

7122121 is an equidigital number, since it uses as much as digits as its factorization.

7122121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 56, while the sum is 16.

The square root of 7122121 is about 2668.7302224092. The cubic root of 7122121 is about 192.3991353301.

Adding to 7122121 its reverse (1212217), we get a palindrome (8334338).

The spelling of 7122121 in words is "seven million, one hundred twenty-two thousand, one hundred twenty-one".