634651789 has 4 divisors (see below), whose sum is σ = 635767740. Its totient is φ = 633535840.

The previous prime is 634651777. The next prime is 634651799. The reversal of 634651789 is 987156436.

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 319873225 + 314778564 = 17885^2 + 17742^2 .

It is a cyclic number.

It is not a de Polignac number, because 634651789 - 2⁵ = 634651757 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 (634651709) 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, 557122 + ... + 558259.

It is an arithmetic number, because the mean of its divisors is an integer number (158941935).

Almost surely, 2^634651789 is an apocalyptic number.

It is an amenable number.

634651789 is a deficient number, since it is larger than the sum of its proper divisors (1115951).

634651789 is a wasteful number, since it uses less digits than its factorization.

634651789 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1115950.

The product of its digits is 1088640, while the sum is 49.

The square root of 634651789 is about 25192.2962232505. The cubic root of 634651789 is about 859.3666641334.

The spelling of 634651789 in words is "six hundred thirty-four million, six hundred fifty-one thousand, seven hundred eighty-nine".