661797229 has 2 divisors, whose sum is σ = 661797230. Its totient is φ = 661797228.

The previous prime is 661797221. The next prime is 661797259. The reversal of 661797229 is 922797166.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 606636900 + 55160329 = 24630^2 + 7427^2 .

It is a cyclic number.

It is not a de Polignac number, because 661797229 - 2³ = 661797221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (661797221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330898614 + 330898615.

It is an arithmetic number, because the mean of its divisors is an integer number (330898615).

Almost surely, 2^661797229 is an apocalyptic number.

It is an amenable number.

661797229 is a deficient number, since it is larger than the sum of its proper divisors (1).

661797229 is an equidigital number, since it uses as much as digits as its factorization.

661797229 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 571536, while the sum is 49.

The square root of 661797229 is about 25725.4198993913. The cubic root of 661797229 is about 871.4483423510.

The spelling of 661797229 in words is "six hundred sixty-one million, seven hundred ninety-seven thousand, two hundred twenty-nine".