21496544689 has 3 divisors (see below), whose sum is σ = 21496691307. Its totient is φ = 21496398072.

The previous prime is 21496544633. The next prime is 21496544723. The reversal of 21496544689 is 98644569412.

It is a happy number.

The square root of 21496544689 is 146617.

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., 11417991025 + 10078553664 = 106855^2 + 100392^2 .

It is not a de Polignac number, because 21496544689 - 2⁹ = 21496544177 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21496542689) 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, 73309 + ... + 219925.

It is an arithmetic number, because the mean of its divisors is an integer number (7165563769).

Almost surely, 2^21496544689 is an apocalyptic number.

21496544689 is the 146617-th square number.

21496544689 is the 73309-th centered octagonal number.

It is an amenable number.

21496544689 is a deficient number, since it is larger than the sum of its proper divisors (146618).

21496544689 is an frugal number, since it uses more digits than its factorization.

21496544689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 293234 (or 146617 counting only the distinct ones).

The product of its digits is 14929920, while the sum is 58.

The spelling of 21496544689 in words is "twenty-one billion, four hundred ninety-six million, five hundred forty-four thousand, six hundred eighty-nine".