521406561 has 8 divisors (see below), whose sum is σ = 748686400. Its totient is φ = 320865552.

The previous prime is 521406559. The next prime is 521406563. The reversal of 521406561 is 165604125.

It is an interprime number because it is at equal distance from previous prime (521406559) and next prime (521406563).

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

It is not a de Polignac number, because 521406561 - 2¹ = 521406559 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (521406563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6684661 + ... + 6684738.

It is an arithmetic number, because the mean of its divisors is an integer number (93585800).

Almost surely, 2^521406561 is an apocalyptic number.

It is an amenable number.

521406561 is a deficient number, since it is larger than the sum of its proper divisors (227279839).

521406561 is a wasteful number, since it uses less digits than its factorization.

521406561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13369415.

The product of its (nonzero) digits is 7200, while the sum is 30.

The square root of 521406561 is about 22834.3285646852. The cubic root of 521406561 is about 804.8695497373.

The spelling of 521406561 in words is "five hundred twenty-one million, four hundred six thousand, five hundred sixty-one".