21794321641 has 3 divisors (see below), whose sum is σ = 21794469271. Its totient is φ = 21794174012.

The previous prime is 21794321611. The next prime is 21794321699. The reversal of 21794321641 is 14612349712.

The square root of 21794321641 is 147629.

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., 1986574041 + 19807747600 = 44571^2 + 140740^2 .

It is not a de Polignac number, because 21794321641 - 2¹¹ = 21794319593 is a prime.

It is a super-3 number, since 3×21794321641³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21794321594 and 21794321603.

It is not an unprimeable number, because it can be changed into a prime (21794321611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 73815 + ... + 221443.

Almost surely, 2^21794321641 is an apocalyptic number.

21794321641 is the 147629-th square number.

21794321641 is the 73815-th centered octagonal number.

It is an amenable number.

21794321641 is a deficient number, since it is larger than the sum of its proper divisors (147630).

21794321641 is an frugal number, since it uses more digits than its factorization.

21794321641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 295258 (or 147629 counting only the distinct ones).

The product of its digits is 72576, while the sum is 40.

The spelling of 21794321641 in words is "twenty-one billion, seven hundred ninety-four million, three hundred twenty-one thousand, six hundred forty-one".