21867137 has 4 divisors (see below), whose sum is σ = 21963696. Its totient is φ = 21770580.

The previous prime is 21867133. The next prime is 21867143. The reversal of 21867137 is 73176812.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21867137 - 2² = 21867133 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21867097 and 21867106.

It is not an unprimeable number, because it can be changed into a prime (21867133) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 47939 + ... + 48392.

It is an arithmetic number, because the mean of its divisors is an integer number (5490924).

Almost surely, 2^21867137 is an apocalyptic number.

It is an amenable number.

21867137 is a deficient number, since it is larger than the sum of its proper divisors (96559).

21867137 is an equidigital number, since it uses as much as digits as its factorization.

21867137 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96558.

The product of its digits is 14112, while the sum is 35.

The square root of 21867137 is about 4676.2310678580. The cubic root of 21867137 is about 279.6387219763.

The spelling of 21867137 in words is "twenty-one million, eight hundred sixty-seven thousand, one hundred thirty-seven".