21729358 has 16 divisors (see below), whose sum is σ = 37636704. Its totient is φ = 9216000.

The previous prime is 21729341. The next prime is 21729361. The reversal of 21729358 is 85392712.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6643 + ... + 9358.

It is an arithmetic number, because the mean of its divisors is an integer number (2352294).

Almost surely, 2^21729358 is an apocalyptic number.

21729358 is a deficient number, since it is larger than the sum of its proper divisors (15907346).

21729358 is a wasteful number, since it uses less digits than its factorization.

21729358 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16107.

The product of its digits is 30240, while the sum is 37.

The square root of 21729358 is about 4661.4759465217. The cubic root of 21729358 is about 279.0501744699.

The spelling of 21729358 in words is "twenty-one million, seven hundred twenty-nine thousand, three hundred fifty-eight".