633478661 has 2 divisors, whose sum is σ = 633478662. Its totient is φ = 633478660.

The previous prime is 633478649. The next prime is 633478663. The reversal of 633478661 is 166874336.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 633478561 + 100 = 25169^2 + 10^2 .

It is a cyclic number.

It is not a de Polignac number, because 633478661 - 2¹⁸ = 633216517 is a prime.

Together with 633478663, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (633478663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 316739330 + 316739331.

It is an arithmetic number, because the mean of its divisors is an integer number (316739331).

Almost surely, 2^633478661 is an apocalyptic number.

It is an amenable number.

633478661 is a deficient number, since it is larger than the sum of its proper divisors (1).

633478661 is an equidigital number, since it uses as much as digits as its factorization.

633478661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 435456, while the sum is 44.

The square root of 633478661 is about 25169.0019865707. The cubic root of 633478661 is about 858.8368361106.

The spelling of 633478661 in words is "six hundred thirty-three million, four hundred seventy-eight thousand, six hundred sixty-one".