21027019 has 4 divisors (see below), whose sum is σ = 22644496. Its totient is φ = 19409544.

The previous prime is 21027007. The next prime is 21027031. The reversal of 21027019 is 91072012.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (21027007) and next prime (21027031).

It is a cyclic number.

It is not a de Polignac number, because 21027019 - 2⁵ = 21026987 is a prime.

It is a super-2 number, since 2×21027019² = 884271056052722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21027049) 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 in 3 ways as a sum of consecutive naturals, for example, 808719 + ... + 808744.

It is an arithmetic number, because the mean of its divisors is an integer number (5661124).

Almost surely, 2^21027019 is an apocalyptic number.

21027019 is a deficient number, since it is larger than the sum of its proper divisors (1617477).

21027019 is a wasteful number, since it uses less digits than its factorization.

21027019 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1617476.

The product of its (nonzero) digits is 252, while the sum is 22.

The square root of 21027019 is about 4585.5227619106. The cubic root of 21027019 is about 276.0106897421.

The spelling of 21027019 in words is "twenty-one million, twenty-seven thousand, nineteen".