21031027 has 2 divisors, whose sum is σ = 21031028. Its totient is φ = 21031026.

The previous prime is 21031019. The next prime is 21031033. The reversal of 21031027 is 72013012.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21031027 - 2³ = 21031019 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21031027.

It is not a weakly prime, because it can be changed into another prime (21031097) 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 as a sum of consecutive naturals, namely, 10515513 + 10515514.

It is an arithmetic number, because the mean of its divisors is an integer number (10515514).

Almost surely, 2^21031027 is an apocalyptic number.

21031027 is a deficient number, since it is larger than the sum of its proper divisors (1).

21031027 is an equidigital number, since it uses as much as digits as its factorization.

21031027 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 84, while the sum is 16.

The square root of 21031027 is about 4585.9597686853. The cubic root of 21031027 is about 276.0282256018.

Adding to 21031027 its reverse (72013012), we get a palindrome (93044039).

The spelling of 21031027 in words is "twenty-one million, thirty-one thousand, twenty-seven".