21456097441 has 9 divisors (see below), whose sum is σ = 22225875763. Its totient is φ = 20712130600.

The previous prime is 21456097433. The next prime is 21456097451. The reversal of 21456097441 is 14479065412.

The square root of 21456097441 is 146479.

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

It can be written as a sum of positive squares in only one way, i.e., 11251057041 + 10205040400 = 106071^2 + 101020^2 .

It is not a de Polignac number, because 21456097441 - 2³ = 21456097433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21456097451) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 4245366 + ... + 4250416.

Almost surely, 2^21456097441 is an apocalyptic number.

21456097441 is the 146479-th square number.

21456097441 is the 73240-th centered octagonal number.

It is an amenable number.

21456097441 is a deficient number, since it is larger than the sum of its proper divisors (769778322).

21456097441 is an frugal number, since it uses more digits than its factorization.

21456097441 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10160 (or 5080 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 43.

The spelling of 21456097441 in words is "twenty-one billion, four hundred fifty-six million, ninety-seven thousand, four hundred forty-one".