635138789 has 4 divisors (see below), whose sum is σ = 635266380. Its totient is φ = 635011200.

The previous prime is 635138759. The next prime is 635138843. The reversal of 635138789 is 987831536.

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 245392225 + 389746564 = 15665^2 + 19742^2 .

It is a cyclic number.

It is not a de Polignac number, because 635138789 - 2¹⁶ = 635073253 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 (635138759) 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, 56012 + ... + 66389.

It is an arithmetic number, because the mean of its divisors is an integer number (158816595).

Almost surely, 2^635138789 is an apocalyptic number.

It is an amenable number.

635138789 is a deficient number, since it is larger than the sum of its proper divisors (127591).

635138789 is a wasteful number, since it uses less digits than its factorization.

635138789 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127590.

The product of its digits is 1088640, while the sum is 50.

The square root of 635138789 is about 25201.9600229823. The cubic root of 635138789 is about 859.5864195804.

The spelling of 635138789 in words is "six hundred thirty-five million, one hundred thirty-eight thousand, seven hundred eighty-nine".