21131434433 has 2 divisors, whose sum is σ = 21131434434. Its totient is φ = 21131434432.

The previous prime is 21131434417. The next prime is 21131434453. The reversal of 21131434433 is 33443413112.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13494771889 + 7636662544 = 116167^2 + 87388^2 .

It is a cyclic number.

It is not a de Polignac number, because 21131434433 - 2⁴ = 21131434417 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21131434396 and 21131434405.

It is not a weakly prime, because it can be changed into another prime (21131434453) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10565717216 + 10565717217.

It is an arithmetic number, because the mean of its divisors is an integer number (10565717217).

Almost surely, 2^21131434433 is an apocalyptic number.

It is an amenable number.

21131434433 is a deficient number, since it is larger than the sum of its proper divisors (1).

21131434433 is an equidigital number, since it uses as much as digits as its factorization.

21131434433 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10368, while the sum is 29.

Adding to 21131434433 its reverse (33443413112), we get a palindrome (54574847545).

The spelling of 21131434433 in words is "twenty-one billion, one hundred thirty-one million, four hundred thirty-four thousand, four hundred thirty-three".