21122019 has 8 divisors (see below), whose sum is σ = 31291920. Its totient is φ = 14081328.

The previous prime is 21122009. The next prime is 21122033. The reversal of 21122019 is 91022112.

It is not a de Polignac number, because 21122019 - 2¹⁷ = 20990947 is a prime.

It is a super-2 number, since 2×21122019² = 892279373272722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21121992 and 21122010.

It is not an unprimeable number, because it can be changed into a prime (21122009) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 391122 + ... + 391175.

It is an arithmetic number, because the mean of its divisors is an integer number (3911490).

Almost surely, 2^21122019 is an apocalyptic number.

21122019 is a deficient number, since it is larger than the sum of its proper divisors (10169901).

21122019 is an equidigital number, since it uses as much as digits as its factorization.

21122019 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 782306 (or 782300 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

The square root of 21122019 is about 4595.8697762230. The cubic root of 21122019 is about 276.4257370918.

The spelling of 21122019 in words is "twenty-one million, one hundred twenty-two thousand, nineteen".