21497584541 has 2 divisors, whose sum is σ = 21497584542. Its totient is φ = 21497584540.

The previous prime is 21497584531. The next prime is 21497584567. The reversal of 21497584541 is 14548579412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16055424100 + 5442160441 = 126710^2 + 73771^2 .

It is a cyclic number.

It is not a de Polignac number, because 21497584541 - 2³⁰ = 20423842717 is a prime.

It is a super-3 number, since 3×21497584541³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21497584541.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21497584531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10748792270 + 10748792271.

It is an arithmetic number, because the mean of its divisors is an integer number (10748792271).

Almost surely, 2^21497584541 is an apocalyptic number.

It is an amenable number.

21497584541 is a deficient number, since it is larger than the sum of its proper divisors (1).

21497584541 is an equidigital number, since it uses as much as digits as its factorization.

21497584541 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1612800, while the sum is 50.

The spelling of 21497584541 in words is "twenty-one billion, four hundred ninety-seven million, five hundred eighty-four thousand, five hundred forty-one".