521770220663 has 4 divisors (see below), whose sum is σ = 534496323648. Its totient is φ = 509044117680.

The previous prime is 521770220651. The next prime is 521770220701. The reversal of 521770220663 is 366022077125.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 521770220663 - 2⁸ = 521770220407 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (41), and also a Moran number because the ratio is a prime number: 12726102943 = 521770220663 / (5 + 2 + 1 + 7 + 7 + 0 + 2 + 2 + 0 + 6 + 6 + 3).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 521770220663.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521770220603) 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, 6363051431 + ... + 6363051512.

It is an arithmetic number, because the mean of its divisors is an integer number (133624080912).

Almost surely, 2^521770220663 is an apocalyptic number.

521770220663 is a deficient number, since it is larger than the sum of its proper divisors (12726102985).

521770220663 is a wasteful number, since it uses less digits than its factorization.

521770220663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12726102984.

The product of its (nonzero) digits is 211680, while the sum is 41.

Adding to 521770220663 its reverse (366022077125), we get a palindrome (887792297788).

The spelling of 521770220663 in words is "five hundred twenty-one billion, seven hundred seventy million, two hundred twenty thousand, six hundred sixty-three".