21010187 has 12 divisors (see below), whose sum is σ = 23488344. Its totient is φ = 18637920.

The previous prime is 21010177. The next prime is 21010189. The reversal of 21010187 is 78101012.

It is not a de Polignac number, because 21010187 - 2⁸ = 21009931 is a prime.

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

It is not an unprimeable number, because it can be changed into a prime (21010189) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19823 + ... + 20855.

It is an arithmetic number, because the mean of its divisors is an integer number (1957362).

Almost surely, 2^21010187 is an apocalyptic number.

21010187 is a deficient number, since it is larger than the sum of its proper divisors (2478157).

21010187 is a wasteful number, since it uses less digits than its factorization.

21010187 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1130 (or 1087 counting only the distinct ones).

The product of its (nonzero) digits is 112, while the sum is 20.

The square root of 21010187 is about 4583.6870530175. The cubic root of 21010187 is about 275.9370217925.

Adding to 21010187 its reverse (78101012), we get a palindrome (99111199).

The spelling of 21010187 in words is "twenty-one million, ten thousand, one hundred eighty-seven".