521670881 has 8 divisors (see below), whose sum is σ = 536561064. Its totient is φ = 506822400.

The previous prime is 521670871. The next prime is 521670887. The reversal of 521670881 is 188076125.

It can be written as a sum of positive squares in 4 ways, for example, as 144961600 + 376709281 = 12040^2 + 19409^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-521670881 is a prime.

It is a super-3 number, since 3×521670881³ (a number of 27 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (521670887) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15881 + ... + 35993.

It is an arithmetic number, because the mean of its divisors is an integer number (67070133).

Almost surely, 2^521670881 is an apocalyptic number.

It is an amenable number.

521670881 is a deficient number, since it is larger than the sum of its proper divisors (14890183).

521670881 is a wasteful number, since it uses less digits than its factorization.

521670881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20851.

The product of its (nonzero) digits is 26880, while the sum is 38.

The square root of 521670881 is about 22840.1156082889. The cubic root of 521670881 is about 805.0055326703.

The spelling of 521670881 in words is "five hundred twenty-one million, six hundred seventy thousand, eight hundred eighty-one".