521387138 has 8 divisors (see below), whose sum is σ = 816084288. Its totient is φ = 249359044.

The previous prime is 521387131. The next prime is 521387147. The reversal of 521387138 is 831783125.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (521387131) 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, 5667206 + ... + 5667297.

It is an arithmetic number, because the mean of its divisors is an integer number (102010536).

Almost surely, 2^521387138 is an apocalyptic number.

521387138 is a deficient number, since it is larger than the sum of its proper divisors (294697150).

521387138 is a wasteful number, since it uses less digits than its factorization.

521387138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11334528.

The product of its digits is 40320, while the sum is 38.

The square root of 521387138 is about 22833.9032580941. The cubic root of 521387138 is about 804.8595555047.

The spelling of 521387138 in words is "five hundred twenty-one million, three hundred eighty-seven thousand, one hundred thirty-eight".