634903019521 has 4 divisors (see below), whose sum is σ = 634907146500. Its totient is φ = 634898892544.

The previous prime is 634903019503. The next prime is 634903019561. The reversal of 634903019521 is 125910309436.

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 602633927025 + 32269092496 = 776295^2 + 179636^2 .

It is a cyclic number.

It is not a de Polignac number, because 634903019521 - 2⁷ = 634903019393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (634903019561) 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, 1823416 + ... + 2143513.

It is an arithmetic number, because the mean of its divisors is an integer number (158726786625).

Almost surely, 2^634903019521 is an apocalyptic number.

It is an amenable number.

634903019521 is a deficient number, since it is larger than the sum of its proper divisors (4126979).

634903019521 is a wasteful number, since it uses less digits than its factorization.

634903019521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4126978.

The product of its (nonzero) digits is 174960, while the sum is 43.

The spelling of 634903019521 in words is "six hundred thirty-four billion, nine hundred three million, nineteen thousand, five hundred twenty-one".