21131434417 has 2 divisors, whose sum is σ = 21131434418. Its totient is φ = 21131434416.

The previous prime is 21131434393. The next prime is 21131434433. The reversal of 21131434417 is 71443413112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20688794896 + 442639521 = 143836^2 + 21039^2 .

It is a cyclic number.

It is not a de Polignac number, because 21131434417 - 2²⁷ = 20997216689 is a prime.

It is not a weakly prime, because it can be changed into another prime (21131431417) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10565717208 + 10565717209.

It is an arithmetic number, because the mean of its divisors is an integer number (10565717209).

Almost surely, 2^21131434417 is an apocalyptic number.

It is an amenable number.

21131434417 is a deficient number, since it is larger than the sum of its proper divisors (1).

21131434417 is an equidigital number, since it uses as much as digits as its factorization.

21131434417 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8064, while the sum is 31.

Adding to 21131434417 its reverse (71443413112), we get a palindrome (92574847529).

The spelling of 21131434417 in words is "twenty-one billion, one hundred thirty-one million, four hundred thirty-four thousand, four hundred seventeen".