21042365129 has 4 divisors (see below), whose sum is σ = 21054168576. Its totient is φ = 21030561684.

The previous prime is 21042365063. The next prime is 21042365131. The reversal of 21042365129 is 92156324012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21042365129 - 2²⁰ = 21041316553 is a prime.

It is a super-2 number, since 2×21042365129² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21042305129) 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, 5899049 + ... + 5902614.

It is an arithmetic number, because the mean of its divisors is an integer number (5263542144).

Almost surely, 2^21042365129 is an apocalyptic number.

It is an amenable number.

21042365129 is a deficient number, since it is larger than the sum of its proper divisors (11803447).

21042365129 is a wasteful number, since it uses less digits than its factorization.

21042365129 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11803446.

The product of its (nonzero) digits is 25920, while the sum is 35.

The spelling of 21042365129 in words is "twenty-one billion, forty-two million, three hundred sixty-five thousand, one hundred twenty-nine".