21429143729 has 4 divisors (see below), whose sum is σ = 24490449984. Its totient is φ = 18367837476.

The previous prime is 21429143719. The next prime is 21429143737. The reversal of 21429143729 is 92734192412.

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 21429143729 - 2⁴ = 21429143713 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21429143729.

It is not an unprimeable number, because it can be changed into a prime (21429143719) 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, 1530653117 + ... + 1530653130.

It is an arithmetic number, because the mean of its divisors is an integer number (6122612496).

Almost surely, 2^21429143729 is an apocalyptic number.

It is an amenable number.

21429143729 is a deficient number, since it is larger than the sum of its proper divisors (3061306255).

21429143729 is an equidigital number, since it uses as much as digits as its factorization.

21429143729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3061306254.

The product of its digits is 217728, while the sum is 44.

The spelling of 21429143729 in words is "twenty-one billion, four hundred twenty-nine million, one hundred forty-three thousand, seven hundred twenty-nine".