7638473281 has 2 divisors, whose sum is σ = 7638473282. Its totient is φ = 7638473280.

The previous prime is 7638473273. The next prime is 7638473329. The reversal of 7638473281 is 1823748367.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5944410000 + 1694063281 = 77100^2 + 41159^2 .

It is a cyclic number.

It is not a de Polignac number, because 7638473281 - 2³ = 7638473273 is a prime.

It is a super-2 number, since 2×7638473281² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (7638474281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3819236640 + 3819236641.

It is an arithmetic number, because the mean of its divisors is an integer number (3819236641).

Almost surely, 2^7638473281 is an apocalyptic number.

It is an amenable number.

7638473281 is a deficient number, since it is larger than the sum of its proper divisors (1).

7638473281 is an equidigital number, since it uses as much as digits as its factorization.

7638473281 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1354752, while the sum is 49.

The square root of 7638473281 is about 87398.3597157292. The cubic root of 7638473281 is about 1969.4071997357.

The spelling of 7638473281 in words is "seven billion, six hundred thirty-eight million, four hundred seventy-three thousand, two hundred eighty-one".