21161267 has 4 divisors (see below), whose sum is σ = 21236856. Its totient is φ = 21085680.

The previous prime is 21161237. The next prime is 21161279. The reversal of 21161267 is 76216112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21161267 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21161227) 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, 37373 + ... + 37934.

It is an arithmetic number, because the mean of its divisors is an integer number (5309214).

Almost surely, 2^21161267 is an apocalyptic number.

21161267 is a deficient number, since it is larger than the sum of its proper divisors (75589).

21161267 is an equidigital number, since it uses as much as digits as its factorization.

21161267 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75588.

The product of its digits is 1008, while the sum is 26.

The square root of 21161267 is about 4600.1377153298. The cubic root of 21161267 is about 276.5968451734.

Adding to 21161267 its reverse (76216112), we get a palindrome (97377379).

The spelling of 21161267 in words is "twenty-one million, one hundred sixty-one thousand, two hundred sixty-seven".