21852187 has 8 divisors (see below), whose sum is σ = 25484000. Its totient is φ = 18730152.

The previous prime is 21852169. The next prime is 21852197. The reversal of 21852187 is 78125812.

It is not a de Polignac number, because 21852187 - 2¹⁵ = 21819419 is a prime.

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

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21852137) 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, 31512 + ... + 32197.

It is an arithmetic number, because the mean of its divisors is an integer number (3185500).

Almost surely, 2^21852187 is an apocalyptic number.

21852187 is a deficient number, since it is larger than the sum of its proper divisors (3631813).

21852187 is an frugal number, since it uses more digits than its factorization.

21852187 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63730 (or 63716 counting only the distinct ones).

The product of its digits is 8960, while the sum is 34.

The square root of 21852187 is about 4674.6322850038. The cubic root of 21852187 is about 279.5749801770.

Adding to 21852187 its reverse (78125812), we get a palindrome (99977999).

The spelling of 21852187 in words is "twenty-one million, eight hundred fifty-two thousand, one hundred eighty-seven".