7091221 has 4 divisors (see below), whose sum is σ = 7099200. Its totient is φ = 7083244.

The previous prime is 7091209. The next prime is 7091233. The reversal of 7091221 is 1221907.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is an interprime number because it is at equal distance from previous prime (7091209) and next prime (7091233).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7091221 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 7091192 and 7091201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7091251) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2461 + ... + 4498.

It is an arithmetic number, because the mean of its divisors is an integer number (1774800).

Almost surely, 2^7091221 is an apocalyptic number.

It is an amenable number.

7091221 is a deficient number, since it is larger than the sum of its proper divisors (7979).

7091221 is a wasteful number, since it uses less digits than its factorization.

7091221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7978.

The product of its (nonzero) digits is 252, while the sum is 22.

The square root of 7091221 is about 2662.9346593561. The cubic root of 7091221 is about 192.1204846347.

The spelling of 7091221 in words is "seven million, ninety-one thousand, two hundred twenty-one".