21187027 has 2 divisors, whose sum is σ = 21187028. Its totient is φ = 21187026.

The previous prime is 21187021. The next prime is 21187063. The reversal of 21187027 is 72078112.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21187027 is a prime.

It is a super-2 number, since 2×21187027² = 897780226197458, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21186986 and 21187004.

It is not a weakly prime, because it can be changed into another prime (21187021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10593513 + 10593514.

It is an arithmetic number, because the mean of its divisors is an integer number (10593514).

Almost surely, 2^21187027 is an apocalyptic number.

21187027 is a deficient number, since it is larger than the sum of its proper divisors (1).

21187027 is an equidigital number, since it uses as much as digits as its factorization.

21187027 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1568, while the sum is 28.

The square root of 21187027 is about 4602.9367799265. The cubic root of 21187027 is about 276.7090351398.

The spelling of 21187027 in words is "twenty-one million, one hundred eighty-seven thousand, twenty-seven".