634826813 has 4 divisors (see below), whose sum is σ = 634994268. Its totient is φ = 634659360.

The previous prime is 634826807. The next prime is 634826837. The reversal of 634826813 is 318628436.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 211208089 + 423618724 = 14533^2 + 20582^2 .

It is a cyclic number.

It is not a de Polignac number, because 634826813 - 2⁸ = 634826557 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 (634826873) 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, 77906 + ... + 85667.

It is an arithmetic number, because the mean of its divisors is an integer number (158748567).

Almost surely, 2^634826813 is an apocalyptic number.

It is an amenable number.

634826813 is a deficient number, since it is larger than the sum of its proper divisors (167455).

634826813 is a wasteful number, since it uses less digits than its factorization.

634826813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167454.

The product of its digits is 165888, while the sum is 41.

The square root of 634826813 is about 25195.7697441455. The cubic root of 634826813 is about 859.4456554632.

The spelling of 634826813 in words is "six hundred thirty-four million, eight hundred twenty-six thousand, eight hundred thirteen".