521106665 has 8 divisors (see below), whose sum is σ = 625612680. Its totient is φ = 416695552.

The previous prime is 521106629. The next prime is 521106671. The reversal of 521106665 is 566601125.

521106665 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 46389721 + 474716944 = 6811^2 + 21788^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 521106665 - 2¹⁴ = 521090281 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11024 + ... + 34113.

It is an arithmetic number, because the mean of its divisors is an integer number (78201585).

Almost surely, 2^521106665 is an apocalyptic number.

It is an amenable number.

521106665 is a deficient number, since it is larger than the sum of its proper divisors (104506015).

521106665 is a wasteful number, since it uses less digits than its factorization.

521106665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47451.

The product of its (nonzero) digits is 10800, while the sum is 32.

The square root of 521106665 is about 22827.7608406957. The cubic root of 521106665 is about 804.7152085963.

The spelling of 521106665 in words is "five hundred twenty-one million, one hundred six thousand, six hundred sixty-five".