21025187 has 2 divisors, whose sum is σ = 21025188. Its totient is φ = 21025186.

The previous prime is 21025163. The next prime is 21025189. The reversal of 21025187 is 78152012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21025187 - 2²⁰ = 19976611 is a prime.

Together with 21025189, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21025189) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10512593 + 10512594.

It is an arithmetic number, because the mean of its divisors is an integer number (10512594).

Almost surely, 2^21025187 is an apocalyptic number.

21025187 is a deficient number, since it is larger than the sum of its proper divisors (1).

21025187 is an equidigital number, since it uses as much as digits as its factorization.

21025187 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1120, while the sum is 26.

The square root of 21025187 is about 4585.3229984375. The cubic root of 21025187 is about 276.0026736071.

Adding to 21025187 its reverse (78152012), we get a palindrome (99177199).

It can be divided in two parts, 21025 and 187, that added together give a palindrome (21212).

The spelling of 21025187 in words is "twenty-one million, twenty-five thousand, one hundred eighty-seven".