20897304481 has 9 divisors (see below), whose sum is σ = 21482859699. Its totient is φ = 20327308344.

The previous prime is 20897304469. The next prime is 20897304509. The reversal of 20897304481 is 18440379802.

The square root of 20897304481 is 144559.

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., 18699195025 + 2198109456 = 136745^2 + 46884^2 .

It is not a de Polignac number, because 20897304481 - 2⁹ = 20897303969 is a prime.

It is a super-2 number, since 2×20897304481² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20897304431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 5346730 + ... + 5350636.

It is an arithmetic number, because the mean of its divisors is an integer number (2386984411).

Almost surely, 2^20897304481 is an apocalyptic number.

20897304481 is the 144559-th square number.

20897304481 is the 72280-th centered octagonal number.

It is an amenable number.

20897304481 is a deficient number, since it is larger than the sum of its proper divisors (585555218).

20897304481 is an frugal number, since it uses more digits than its factorization.

20897304481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7888 (or 3944 counting only the distinct ones).

The product of its (nonzero) digits is 387072, while the sum is 46.

The spelling of 20897304481 in words is "twenty billion, eight hundred ninety-seven million, three hundred four thousand, four hundred eighty-one".