521117605 has 4 divisors (see below), whose sum is σ = 625341132. Its totient is φ = 416894080.

The previous prime is 521117603. The next prime is 521117621. The reversal of 521117605 is 506711125.

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 63457156 + 457660449 = 7966^2 + 21393^2 .

It is not a de Polignac number, because 521117605 - 2¹ = 521117603 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 (521117603) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 52111756 + ... + 52111765.

It is an arithmetic number, because the mean of its divisors is an integer number (156335283).

Almost surely, 2^521117605 is an apocalyptic number.

It is an amenable number.

521117605 is a deficient number, since it is larger than the sum of its proper divisors (104223527).

521117605 is a wasteful number, since it uses less digits than its factorization.

521117605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104223526.

The product of its (nonzero) digits is 2100, while the sum is 28.

The square root of 521117605 is about 22828.0004599614. Note that the first 3 decimals coincide. The cubic root of 521117605 is about 804.7208398955.

The spelling of 521117605 in words is "five hundred twenty-one million, one hundred seventeen thousand, six hundred five".