20109420 has 72 divisors (see below), whose sum is σ = 62322624. Its totient is φ = 5246208.

The previous prime is 20109413. The next prime is 20109431. The reversal of 20109420 is 2490102.

20109420 = T₂₄₃ + T₂₄₄ + ... + T₅₁₂.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 20109393 and 20109402.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7272 + ... + 9648.

It is an arithmetic number, because the mean of its divisors is an integer number (865592).

Almost surely, 2^20109420 is an apocalyptic number.

20109420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20109420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31161312).

20109420 is an abundant number, since it is smaller than the sum of its proper divisors (42213204).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20109420 is a wasteful number, since it uses less digits than its factorization.

20109420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2439 (or 2434 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 20109420 is about 4484.3527961123. The cubic root of 20109420 is about 271.9358809359.

Adding to 20109420 its reverse (2490102), we get a palindrome (22599522).

The spelling of 20109420 in words is "twenty million, one hundred nine thousand, four hundred twenty".