321726049681 has 3 divisors (see below), whose sum is σ = 321726616891. Its totient is φ = 321725482472.

The previous prime is 321726049663. The next prime is 321726049693. The reversal of 321726049681 is 186940627123.

It is a happy number.

The square root of 321726049681 is 567209.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 63499464081 + 258226585600 = 251991^2 + 508160^2 .

It is not a de Polignac number, because 321726049681 - 2¹³ = 321726041489 is a prime.

It is a super-2 number, since 2×321726049681² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (321726049651) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 283605 + ... + 850813.

Almost surely, 2^321726049681 is an apocalyptic number.

321726049681 is the 567209-th square number.

321726049681 is the 283605-th centered octagonal number.

It is an amenable number.

321726049681 is a deficient number, since it is larger than the sum of its proper divisors (567210).

321726049681 is an frugal number, since it uses more digits than its factorization.

321726049681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1134418 (or 567209 counting only the distinct ones).

The product of its (nonzero) digits is 870912, while the sum is 49.

Multiplying 321726049681 by its sum of digits (49), we get a square (15764576434369 = 3970463²).

The spelling of 321726049681 in words is "three hundred twenty-one billion, seven hundred twenty-six million, forty-nine thousand, six hundred eighty-one".