21621266532337 has 2 divisors, whose sum is σ = 21621266532338. Its totient is φ = 21621266532336.

The previous prime is 21621266532251. The next prime is 21621266532347. The reversal of 21621266532337 is 73323566212612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14919671034801 + 6701595497536 = 3862599^2 + 2588744^2 .

It is a cyclic number.

It is not a de Polignac number, because 21621266532337 - 2¹⁹ = 21621266008049 is a prime.

It is not a weakly prime, because it can be changed into another prime (21621266532347) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10810633266168 + 10810633266169.

It is an arithmetic number, because the mean of its divisors is an integer number (10810633266169).

Almost surely, 2^{21621266532337} is an apocalyptic number.

It is an amenable number.

21621266532337 is a deficient number, since it is larger than the sum of its proper divisors (1).

21621266532337 is an equidigital number, since it uses as much as digits as its factorization.

21621266532337 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3265920, while the sum is 49.

The spelling of 21621266532337 in words is "twenty-one trillion, six hundred twenty-one billion, two hundred sixty-six million, five hundred thirty-two thousand, three hundred thirty-seven".