21231431029 has 2 divisors, whose sum is σ = 21231431030. Its totient is φ = 21231431028.

The previous prime is 21231431027. The next prime is 21231431069. The reversal of 21231431029 is 92013413212.

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., 13525224804 + 7706206225 = 116298^2 + 87785^2 .

It is a cyclic number.

It is not a de Polignac number, because 21231431029 - 2¹ = 21231431027 is a prime.

Together with 21231431027, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 21231430988 and 21231431006.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21231431027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10615715514 + 10615715515.

It is an arithmetic number, because the mean of its divisors is an integer number (10615715515).

Almost surely, 2^21231431029 is an apocalyptic number.

It is an amenable number.

21231431029 is a deficient number, since it is larger than the sum of its proper divisors (1).

21231431029 is an equidigital number, since it uses as much as digits as its factorization.

21231431029 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2592, while the sum is 28.

The spelling of 21231431029 in words is "twenty-one billion, two hundred thirty-one million, four hundred thirty-one thousand, twenty-nine".