21742648497 has 6 divisors (see below), whose sum is σ = 31406047842. Its totient is φ = 14495098992.

The previous prime is 21742648493. The next prime is 21742648519. The reversal of 21742648497 is 79484624712.

21742648497 is a `hidden beast` number, since 2 + 1 + 74 + 2 + 6 + 484 + 97 = 666.

It can be written as a sum of positive squares in only one way, i.e., 14785587216 + 6957061281 = 121596^2 + 83409^2 .

It is not a de Polignac number, because 21742648497 - 2² = 21742648493 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21742648493) 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, 1207924908 + ... + 1207924925.

It is an arithmetic number, because the mean of its divisors is an integer number (5234341307).

Almost surely, 2^21742648497 is an apocalyptic number.

It is an amenable number.

21742648497 is a deficient number, since it is larger than the sum of its proper divisors (9663399345).

21742648497 is a wasteful number, since it uses less digits than its factorization.

21742648497 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2415849839 (or 2415849836 counting only the distinct ones).

The product of its digits is 5419008, while the sum is 54.

The spelling of 21742648497 in words is "twenty-one billion, seven hundred forty-two million, six hundred forty-eight thousand, four hundred ninety-seven".