21434222155517 has 2 divisors, whose sum is σ = 21434222155518. Its totient is φ = 21434222155516.

The previous prime is 21434222155459. The next prime is 21434222155523. The reversal of 21434222155517 is 71555122243412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16642002050521 + 4792220104996 = 4079461^2 + 2189114^2 .

It is a cyclic number.

It is not a de Polignac number, because 21434222155517 - 2¹² = 21434222151421 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21434222155117) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10717111077758 + 10717111077759.

It is an arithmetic number, because the mean of its divisors is an integer number (10717111077759).

Almost surely, 2^{21434222155517} is an apocalyptic number.

It is an amenable number.

21434222155517 is a deficient number, since it is larger than the sum of its proper divisors (1).

21434222155517 is an equidigital number, since it uses as much as digits as its factorization.

21434222155517 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 672000, while the sum is 44.

Adding to 21434222155517 its reverse (71555122243412), we get a palindrome (92989344398929).

The spelling of 21434222155517 in words is "twenty-one trillion, four hundred thirty-four billion, two hundred twenty-two million, one hundred fifty-five thousand, five hundred seventeen".