21739329 has 12 divisors (see below), whose sum is σ = 31449600. Its totient is φ = 14470584.

The previous prime is 21739321. The next prime is 21739351. The reversal of 21739329 is 92393712.

It is not a de Polignac number, because 21739329 - 2³ = 21739321 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21739293 and 21739302.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21739321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6112 + ... + 8990.

It is an arithmetic number, because the mean of its divisors is an integer number (2620800).

Almost surely, 2^21739329 is an apocalyptic number.

It is an amenable number.

21739329 is a deficient number, since it is larger than the sum of its proper divisors (9710271).

21739329 is a wasteful number, since it uses less digits than its factorization.

21739329 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3724 (or 3721 counting only the distinct ones).

The product of its digits is 20412, while the sum is 36.

The square root of 21739329 is about 4662.5453349002. The cubic root of 21739329 is about 279.0928507393.

The spelling of 21739329 in words is "twenty-one million, seven hundred thirty-nine thousand, three hundred twenty-nine".