20421219 has 64 divisors (see below), whose sum is σ = 36700160. Its totient is φ = 9797760.

The previous prime is 20421209. The next prime is 20421223. The reversal of 20421219 is 91212402.

It is not a de Polignac number, because 20421219 - 2⁵ = 20421187 is a prime.

It is a super-2 number, since 2×20421219² = 834052370891922, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a junction number, because it is equal to n+sod(n) for n = 20421195 and 20421204.

It is not an unprimeable number, because it can be changed into a prime (20421209) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 160734 + ... + 160860.

It is an arithmetic number, because the mean of its divisors is an integer number (573440).

Almost surely, 2^20421219 is an apocalyptic number.

20421219 is a deficient number, since it is larger than the sum of its proper divisors (16278941).

20421219 is a wasteful number, since it uses less digits than its factorization.

20421219 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 200.

The product of its (nonzero) digits is 288, while the sum is 21.

The square root of 20421219 is about 4518.9842885321. The cubic root of 20421219 is about 273.3341451823.

The spelling of 20421219 in words is "twenty million, four hundred twenty-one thousand, two hundred nineteen".