21498760917 has 6 divisors (see below), whose sum is σ = 31053765782. Its totient is φ = 14332507272.

The previous prime is 21498760837. The next prime is 21498760939. The reversal of 21498760917 is 71906789412.

21498760917 is a `hidden beast` number, since 2 + 1 + 498 + 7 + 60 + 91 + 7 = 666.

It can be written as a sum of positive squares in only one way, i.e., 20747233521 + 751527396 = 144039^2 + 27414^2 .

It is not a de Polignac number, because 21498760917 - 2¹² = 21498756821 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21498760117) 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, 1194375598 + ... + 1194375615.

Almost surely, 2^21498760917 is an apocalyptic number.

It is an amenable number.

21498760917 is a deficient number, since it is larger than the sum of its proper divisors (9555004865).

21498760917 is a wasteful number, since it uses less digits than its factorization.

21498760917 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2388751219 (or 2388751216 counting only the distinct ones).

The product of its (nonzero) digits is 1524096, while the sum is 54.

The spelling of 21498760917 in words is "twenty-one billion, four hundred ninety-eight million, seven hundred sixty thousand, nine hundred seventeen".