7278231281 has 2 divisors, whose sum is σ = 7278231282. Its totient is φ = 7278231280.

The previous prime is 7278231203. The next prime is 7278231329. The reversal of 7278231281 is 1821328727.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5125271281 + 2152960000 = 71591^2 + 46400^2 .

It is a cyclic number.

It is not a de Polignac number, because 7278231281 - 2¹⁰ = 7278230257 is a prime.

It is a super-2 number, since 2×7278231281² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (7278239281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3639115640 + 3639115641.

It is an arithmetic number, because the mean of its divisors is an integer number (3639115641).

Almost surely, 2^7278231281 is an apocalyptic number.

It is an amenable number.

7278231281 is a deficient number, since it is larger than the sum of its proper divisors (1).

7278231281 is an equidigital number, since it uses as much as digits as its factorization.

7278231281 is an evil number, because the sum of its binary digits is even.

The product of its digits is 75264, while the sum is 41.

The square root of 7278231281 is about 85312.5505479704. The cubic root of 7278231281 is about 1937.9472460180.

The spelling of 7278231281 in words is "seven billion, two hundred seventy-eight million, two hundred thirty-one thousand, two hundred eighty-one".