21506205451219 has 2 divisors, whose sum is σ = 21506205451220. Its totient is φ = 21506205451218.

The previous prime is 21506205451177. The next prime is 21506205451261. The reversal of 21506205451219 is 91215450260512.

It is a balanced prime because it is at equal distance from previous prime (21506205451177) and next prime (21506205451261).

It is a cyclic number.

It is not a de Polignac number, because 21506205451219 - 2²¹ = 21506203354067 is a prime.

It is a super-2 number, since 2×21506205451219² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21506205451319) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10753102725609 + 10753102725610.

It is an arithmetic number, because the mean of its divisors is an integer number (10753102725610).

Almost surely, 2^{21506205451219} is an apocalyptic number.

21506205451219 is a deficient number, since it is larger than the sum of its proper divisors (1).

21506205451219 is an equidigital number, since it uses as much as digits as its factorization.

21506205451219 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 216000, while the sum is 43.

The spelling of 21506205451219 in words is "twenty-one trillion, five hundred six billion, two hundred five million, four hundred fifty-one thousand, two hundred nineteen".