21059019 has 12 divisors (see below), whose sum is σ = 30689256. Its totient is φ = 13914432.

The previous prime is 21058997. The next prime is 21059021. The reversal of 21059019 is 91095012.

It is a happy number.

It is not a de Polignac number, because 21059019 - 2⁵ = 21058987 is a prime.

It is a super-2 number, since 2×21059019² = 886964562484722, which contains 22 as substring.

It is a Smith number, since the sum of its digits (27) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 21058983 and 21059001.

It is not an unprimeable number, because it can be changed into a prime (21059029) 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, 9337 + ... + 11370.

It is an arithmetic number, because the mean of its divisors is an integer number (2557438).

Almost surely, 2^21059019 is an apocalyptic number.

21059019 is a deficient number, since it is larger than the sum of its proper divisors (9630237).

21059019 is a wasteful number, since it uses less digits than its factorization.

21059019 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20826 (or 20823 counting only the distinct ones).

The product of its (nonzero) digits is 810, while the sum is 27.

The square root of 21059019 is about 4589.0106776951. The cubic root of 21059019 is about 276.1506345333.

The spelling of 21059019 in words is "twenty-one million, fifty-nine thousand, nineteen".