21233729 has 16 divisors (see below), whose sum is σ = 24267264. Its totient is φ = 18403200.

The previous prime is 21233689. The next prime is 21233753. The reversal of 21233729 is 92733212.

It is a cyclic number.

It is not a de Polignac number, because 21233729 - 2¹² = 21229633 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21233029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24467 + ... + 25319.

It is an arithmetic number, because the mean of its divisors is an integer number (1516704).

Almost surely, 2^21233729 is an apocalyptic number.

It is an amenable number.

21233729 is a deficient number, since it is larger than the sum of its proper divisors (3033535).

21233729 is a wasteful number, since it uses less digits than its factorization.

21233729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 968.

The product of its digits is 4536, while the sum is 29.

The square root of 21233729 is about 4608.0070529460. The cubic root of 21233729 is about 276.9122000575.

The spelling of 21233729 in words is "twenty-one million, two hundred thirty-three thousand, seven hundred twenty-nine".