634226561 has 2 divisors, whose sum is σ = 634226562. Its totient is φ = 634226560.

The previous prime is 634226533. The next prime is 634226563. The reversal of 634226561 is 165622436.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 444999025 + 189227536 = 21095^2 + 13756^2 .

It is a cyclic number.

It is not a de Polignac number, because 634226561 - 2¹⁸ = 633964417 is a prime.

Together with 634226563, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (634226563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 317113280 + 317113281.

It is an arithmetic number, because the mean of its divisors is an integer number (317113281).

Almost surely, 2^634226561 is an apocalyptic number.

It is an amenable number.

634226561 is a deficient number, since it is larger than the sum of its proper divisors (1).

634226561 is an equidigital number, since it uses as much as digits as its factorization.

634226561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 51840, while the sum is 35.

The square root of 634226561 is about 25183.8551655619. The cubic root of 634226561 is about 859.1746909292.

Adding to 634226561 its reverse (165622436), we get a palindrome (799848997).

The spelling of 634226561 in words is "six hundred thirty-four million, two hundred twenty-six thousand, five hundred sixty-one".