7156221 has 8 divisors (see below), whose sum is σ = 9576480. Its totient is φ = 4753392.

The previous prime is 7156213. The next prime is 7156229. The reversal of 7156221 is 1226517.

It is an interprime number because it is at equal distance from previous prime (7156213) and next prime (7156229).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 7156221 - 2³ = 7156213 is a prime.

It is a super-2 number, since 2×7156221² = 102422998001682, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 7156191 and 7156200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7156229) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3366 + ... + 5063.

It is an arithmetic number, because the mean of its divisors is an integer number (1197060).

Almost surely, 2^7156221 is an apocalyptic number.

It is an amenable number.

7156221 is a deficient number, since it is larger than the sum of its proper divisors (2420259).

7156221 is a wasteful number, since it uses less digits than its factorization.

7156221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8715.

The product of its digits is 840, while the sum is 24.

The square root of 7156221 is about 2675.1113995496. Note that the first 3 decimals coincide. The cubic root of 7156221 is about 192.7057091463.

The spelling of 7156221 in words is "seven million, one hundred fifty-six thousand, two hundred twenty-one".