7215121 has 2 divisors, whose sum is σ = 7215122. Its totient is φ = 7215120.

The previous prime is 7215119. The next prime is 7215127. The reversal of 7215121 is 1215127.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7102225 + 112896 = 2665^2 + 336^2 .

It is a cyclic number.

It is not a de Polignac number, because 7215121 - 2¹ = 7215119 is a prime.

Together with 7215119, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (7215127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3607560 + 3607561.

It is an arithmetic number, because the mean of its divisors is an integer number (3607561).

Almost surely, 2^7215121 is an apocalyptic number.

It is an amenable number.

7215121 is a deficient number, since it is larger than the sum of its proper divisors (1).

7215121 is an equidigital number, since it uses as much as digits as its factorization.

7215121 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 7215121 is about 2686.0977271872. The cubic root of 7215121 is about 193.2329598545.

The spelling of 7215121 in words is "seven million, two hundred fifteen thousand, one hundred twenty-one".