21616129 has 8 divisors (see below), whose sum is σ = 24092640. Its totient is φ = 19273536.

The previous prime is 21616123. The next prime is 21616139. The reversal of 21616129 is 92161612.

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

It is a cyclic number.

It is not a de Polignac number, because 21616129 - 2⁹ = 21615617 is a prime.

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

It is a Duffinian number.

It is a plaindrome in base 11.

It is a junction number, because it is equal to n+sod(n) for n = 21616097 and 21616106.

It is not an unprimeable number, because it can be changed into a prime (21616123) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33139 + ... + 33784.

It is an arithmetic number, because the mean of its divisors is an integer number (3011580).

Almost surely, 2^21616129 is an apocalyptic number.

It is an amenable number.

21616129 is a deficient number, since it is larger than the sum of its proper divisors (2476511).

21616129 is a wasteful number, since it uses less digits than its factorization.

21616129 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66959.

The product of its digits is 1296, while the sum is 28.

The square root of 21616129 is about 4649.3148957669. The cubic root of 21616129 is about 278.5646314612.

The spelling of 21616129 in words is "twenty-one million, six hundred sixteen thousand, one hundred twenty-nine".