21103161 has 8 divisors (see below), whose sum is σ = 28167360. Its totient is φ = 14053872.

The previous prime is 21103139. The next prime is 21103177. The reversal of 21103161 is 16130112.

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

It is not a de Polignac number, because 21103161 - 2¹⁵ = 21070393 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21103161.

It is not an unprimeable number, because it can be changed into a prime (21103961) 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, 156 + ... + 6498.

It is an arithmetic number, because the mean of its divisors is an integer number (3520920).

Almost surely, 2^21103161 is an apocalyptic number.

It is an amenable number.

21103161 is a deficient number, since it is larger than the sum of its proper divisors (7064199).

21103161 is a wasteful number, since it uses less digits than its factorization.

21103161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7455.

The product of its (nonzero) digits is 36, while the sum is 15.

The square root of 21103161 is about 4593.8176933788. The cubic root of 21103161 is about 276.3434471573.

Adding to 21103161 its reverse (16130112), we get a palindrome (37233273).

The spelling of 21103161 in words is "twenty-one million, one hundred three thousand, one hundred sixty-one".