21936240449 has 6 divisors (see below), whose sum is σ = 23151545010. Its totient is φ = 20781701136.

The previous prime is 21936240433. The next prime is 21936240463. The reversal of 21936240449 is 94404263912.

It can be written as a sum of positive squares in only one way, i.e., 20414694400 + 1521546049 = 142880^2 + 39007^2 .

It is not a de Polignac number, because 21936240449 - 2⁴ = 21936240433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21936240419) 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, 30382244 + ... + 30382965.

It is an arithmetic number, because the mean of its divisors is an integer number (3858590835).

Almost surely, 2^21936240449 is an apocalyptic number.

It is an amenable number.

21936240449 is a deficient number, since it is larger than the sum of its proper divisors (1215304561).

21936240449 is an equidigital number, since it uses as much as digits as its factorization.

21936240449 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60765247 (or 60765228 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 44.

The spelling of 21936240449 in words is "twenty-one billion, nine hundred thirty-six million, two hundred forty thousand, four hundred forty-nine".