21330838957537 has 2 divisors, whose sum is σ = 21330838957538. Its totient is φ = 21330838957536.

The previous prime is 21330838957531. The next prime is 21330838957541. The reversal of 21330838957537 is 73575983803312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19448443981521 + 1882394976016 = 4410039^2 + 1372004^2 .

It is a cyclic number.

It is not a de Polignac number, because 21330838957537 - 2⁷ = 21330838957409 is a prime.

It is not a weakly prime, because it can be changed into another prime (21330838957531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10665419478768 + 10665419478769.

It is an arithmetic number, because the mean of its divisors is an integer number (10665419478769).

Almost surely, 2^{21330838957537} is an apocalyptic number.

It is an amenable number.

21330838957537 is a deficient number, since it is larger than the sum of its proper divisors (1).

21330838957537 is an equidigital number, since it uses as much as digits as its factorization.

21330838957537 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 114307200, while the sum is 64.

The spelling of 21330838957537 in words is "twenty-one trillion, three hundred thirty billion, eight hundred thirty-eight million, nine hundred fifty-seven thousand, five hundred thirty-seven".