21729934 has 8 divisors (see below), whose sum is σ = 32637528. Its totient is φ = 10850760.

The previous prime is 21729931. The next prime is 21729937. The reversal of 21729934 is 43992712.

It is an interprime number because it is at equal distance from previous prime (21729931) and next prime (21729937).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 21729893 and 21729902.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21729931) 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, 5077 + ... + 8320.

It is an arithmetic number, because the mean of its divisors is an integer number (4079691).

Almost surely, 2^21729934 is an apocalyptic number.

21729934 is a deficient number, since it is larger than the sum of its proper divisors (10907594).

21729934 is a wasteful number, since it uses less digits than its factorization.

21729934 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14210.

The product of its digits is 27216, while the sum is 37.

The square root of 21729934 is about 4661.5377291190. The cubic root of 21729934 is about 279.0526401277.

The spelling of 21729934 in words is "twenty-one million, seven hundred twenty-nine thousand, nine hundred thirty-four".