521612321623 has 8 divisors (see below), whose sum is σ = 523037043360. Its totient is φ = 520189050240.

The previous prime is 521612321617. The next prime is 521612321663. The reversal of 521612321623 is 326123216125.

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

It is a cyclic number.

It is not a de Polignac number, because 521612321623 - 2¹⁷ = 521612190551 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 (521612321603) 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, 359643 + ... + 1082851.

It is an arithmetic number, because the mean of its divisors is an integer number (65379630420).

Almost surely, 2^521612321623 is an apocalyptic number.

521612321623 is a deficient number, since it is larger than the sum of its proper divisors (1424721737).

521612321623 is a wasteful number, since it uses less digits than its factorization.

521612321623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 725177.

The product of its digits is 25920, while the sum is 34.

Adding to 521612321623 its reverse (326123216125), we get a palindrome (847735537748).

The spelling of 521612321623 in words is "five hundred twenty-one billion, six hundred twelve million, three hundred twenty-one thousand, six hundred twenty-three".