7225781 has 2 divisors, whose sum is σ = 7225782. Its totient is φ = 7225780.

The previous prime is 7225747. The next prime is 7225783. The reversal of 7225781 is 1875227.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4990756 + 2235025 = 2234^2 + 1495^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7225781 is a prime.

It is a super-2 number, since 2×7225781² = 104423822119922, which contains 22 as substring.

Together with 7225783, it forms a pair of twin primes.

It is a Chen prime.

It is equal to p₄₉₀₉₅₅ and since 7225781 and 490955 have the same sum of digits, it is a Honaker prime.

It is a nialpdrome in base 5.

It is a zygodrome in base 5.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7225783) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3612890 + 3612891.

It is an arithmetic number, because the mean of its divisors is an integer number (3612891).

Almost surely, 2^7225781 is an apocalyptic number.

It is an amenable number.

7225781 is a deficient number, since it is larger than the sum of its proper divisors (1).

7225781 is an equidigital number, since it uses as much as digits as its factorization.

7225781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7840, while the sum is 32.

The square root of 7225781 is about 2688.0812859733. The cubic root of 7225781 is about 193.3280772121.

The spelling of 7225781 in words is "seven million, two hundred twenty-five thousand, seven hundred eighty-one".