21042329 has 24 divisors (see below), whose sum is σ = 27724608. Its totient is φ = 15513120.

The previous prime is 21042319. The next prime is 21042347. The reversal of 21042329 is 92324012.

It is a de Polignac number, because none of the positive numbers 2^k-21042329 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21042319) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 27419 + ... + 28175.

It is an arithmetic number, because the mean of its divisors is an integer number (1155192).

Almost surely, 2^21042329 is an apocalyptic number.

It is an amenable number.

21042329 is a deficient number, since it is larger than the sum of its proper divisors (6682279).

21042329 is a wasteful number, since it uses less digits than its factorization.

21042329 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 813 (or 794 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 21042329 is about 4587.1918425111. The cubic root of 21042329 is about 276.0776622799.

The spelling of 21042329 in words is "twenty-one million, forty-two thousand, three hundred twenty-nine".