634591 has 4 divisors (see below), whose sum is σ = 639000. Its totient is φ = 630184.

The previous prime is 634577. The next prime is 634597. The reversal of 634591 is 195436.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 634591 - 2⁹ = 634079 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (634597) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1981 + ... + 2278.

It is an arithmetic number, because the mean of its divisors is an integer number (159750).

2⁶³⁴⁵⁹¹ is an apocalyptic number.

634591 is a deficient number, since it is larger than the sum of its proper divisors (4409).

634591 is a wasteful number, since it uses less digits than its factorization.

634591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4408.

The product of its digits is 3240, while the sum is 28.

The square root of 634591 is about 796.6122017644. The cubic root of 634591 is about 85.9339225618.

It can be divided in two parts, 634 and 591, that added together give a triangular number (1225 = T₄₉).

The spelling of 634591 in words is "six hundred thirty-four thousand, five hundred ninety-one".