21616329 has 8 divisors (see below), whose sum is σ = 32939200. Its totient is φ = 12352176.

The previous prime is 21616327. The next prime is 21616337. The reversal of 21616329 is 92361612.

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

It is not a de Polignac number, because 21616329 - 2¹ = 21616327 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a junction number, because it is equal to n+sod(n) for n = 21616296 and 21616305.

It is not an unprimeable number, because it can be changed into a prime (21616327) 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 7 ways as a sum of consecutive naturals, for example, 514654 + ... + 514695.

It is an arithmetic number, because the mean of its divisors is an integer number (4117400).

Almost surely, 2^21616329 is an apocalyptic number.

It is an amenable number.

21616329 is a deficient number, since it is larger than the sum of its proper divisors (11322871).

21616329 is a wasteful number, since it uses less digits than its factorization.

21616329 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1029359.

The product of its digits is 3888, while the sum is 30.

The square root of 21616329 is about 4649.3364042624. The cubic root of 21616329 is about 278.5654905844.

It can be divided in two parts, 21616 and 329, that added together give a triangular number (21945 = T₂₀₉).

The spelling of 21616329 in words is "twenty-one million, six hundred sixteen thousand, three hundred twenty-nine".