21115223029 has 4 divisors (see below), whose sum is σ = 21119263276. Its totient is φ = 21111182784.

The previous prime is 21115223027. The next prime is 21115223039. The reversal of 21115223029 is 92032251112.

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 10737726129 + 10377496900 = 103623^2 + 101870^2 .

It is a cyclic number.

It is not a de Polignac number, because 21115223029 - 2¹ = 21115223027 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21115222988 and 21115223006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21115223027) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2012274 + ... + 2022739.

It is an arithmetic number, because the mean of its divisors is an integer number (5279815819).

Almost surely, 2^21115223029 is an apocalyptic number.

It is an amenable number.

21115223029 is a deficient number, since it is larger than the sum of its proper divisors (4040247).

21115223029 is an equidigital number, since it uses as much as digits as its factorization.

21115223029 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4040246.

The product of its (nonzero) digits is 2160, while the sum is 28.

The spelling of 21115223029 in words is "twenty-one billion, one hundred fifteen million, two hundred twenty-three thousand, twenty-nine".