521871655753664 has 112 divisors (see below), whose sum is σ = 1099276741154592. Its totient is φ = 244966513999872.

The previous prime is 521871655753663. The next prime is 521871655753697. The reversal of 521871655753664 is 466357556178125.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521871655753663) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1329490994 + ... + 1329883470.

It is an arithmetic number, because the mean of its divisors is an integer number (9814970903166).

Almost surely, 2^{521871655753664} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 521871655753664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (549638370577296).

521871655753664 is an abundant number, since it is smaller than the sum of its proper divisors (577405085400928).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

521871655753664 is a wasteful number, since it uses less digits than its factorization.

521871655753664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 395590 (or 395580 counting only the distinct ones).

The product of its digits is 1270080000, while the sum is 71.

The spelling of 521871655753664 in words is "five hundred twenty-one trillion, eight hundred seventy-one billion, six hundred fifty-five million, seven hundred fifty-three thousand, six hundred sixty-four".