21131442029 has 4 divisors (see below), whose sum is σ = 21181635900. Its totient is φ = 21081248160.

The previous prime is 21131442023. The next prime is 21131442053. The reversal of 21131442029 is 92024413112.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 810939529 + 20320502500 = 28477^2 + 142550^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21131442029 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21131441992 and 21131442010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21131442023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25096304 + ... + 25097145.

It is an arithmetic number, because the mean of its divisors is an integer number (5295408975).

Almost surely, 2^21131442029 is an apocalyptic number.

It is an amenable number.

21131442029 is a deficient number, since it is larger than the sum of its proper divisors (50193871).

21131442029 is an equidigital number, since it uses as much as digits as its factorization.

21131442029 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50193870.

The product of its (nonzero) digits is 3456, while the sum is 29.

The spelling of 21131442029 in words is "twenty-one billion, one hundred thirty-one million, four hundred forty-two thousand, twenty-nine".