634861 has 2 divisors, whose sum is σ = 634862. Its totient is φ = 634860.

The previous prime is 634859. The next prime is 634871. The reversal of 634861 is 168436.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 562500 + 72361 = 750^2 + 269^2 .

It is a cyclic number.

It is not a de Polignac number, because 634861 - 2¹ = 634859 is a prime.

Together with 634859, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (634841) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 317430 + 317431.

It is an arithmetic number, because the mean of its divisors is an integer number (317431).

2⁶³⁴⁸⁶¹ is an apocalyptic number.

It is an amenable number.

634861 is a deficient number, since it is larger than the sum of its proper divisors (1).

634861 is an equidigital number, since it uses as much as digits as its factorization.

634861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3456, while the sum is 28.

The square root of 634861 is about 796.7816513952. The cubic root of 634861 is about 85.9461082947.

The spelling of 634861 in words is "six hundred thirty-four thousand, eight hundred sixty-one".