21731184097 has 6 divisors (see below), whose sum is σ = 25279132578. Its totient is φ = 18626729184.

The previous prime is 21731184091. The next prime is 21731184119. The reversal of 21731184097 is 79048113712.

It can be written as a sum of positive squares in only one way, i.e., 12785051041 + 8946133056 = 113071^2 + 94584^2 .

It is not a de Polignac number, because 21731184097 - 2¹¹ = 21731182049 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21731184091) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 221746728 + ... + 221746825.

It is an arithmetic number, because the mean of its divisors is an integer number (4213188763).

Almost surely, 2^21731184097 is an apocalyptic number.

It is an amenable number.

21731184097 is a deficient number, since it is larger than the sum of its proper divisors (3547948481).

21731184097 is an equidigital number, since it uses as much as digits as its factorization.

21731184097 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 443493567 (or 443493560 counting only the distinct ones).

The product of its (nonzero) digits is 84672, while the sum is 43.

The spelling of 21731184097 in words is "twenty-one billion, seven hundred thirty-one million, one hundred eighty-four thousand, ninety-seven".