521045151505421 has 4 divisors (see below), whose sum is σ = 521481903519612. Its totient is φ = 520608399491232.

The previous prime is 521045151505393. The next prime is 521045151505453. The reversal of 521045151505421 is 124505151540125.

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 341451783955396 + 179593367550025 = 18478414^2 + 13401245^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-521045151505421 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 (521045181505421) 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, 218376005306 + ... + 218376007691.

It is an arithmetic number, because the mean of its divisors is an integer number (130370475879903).

Almost surely, 2^{521045151505421} is an apocalyptic number.

It is an amenable number.

521045151505421 is a deficient number, since it is larger than the sum of its proper divisors (436752014191).

521045151505421 is a wasteful number, since it uses less digits than its factorization.

521045151505421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 436752014190.

The product of its (nonzero) digits is 200000, while the sum is 41.

The spelling of 521045151505421 in words is "five hundred twenty-one trillion, forty-five billion, one hundred fifty-one million, five hundred five thousand, four hundred twenty-one".