20409372 has 54 divisors (see below), whose sum is σ = 54178488. Its totient is φ = 6465888.

The previous prime is 20409371. The next prime is 20409383. The reversal of 20409372 is 27390402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20409371) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 129918 + ... + 130074.

Almost surely, 2^20409372 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20409372, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27089244).

20409372 is an abundant number, since it is smaller than the sum of its proper divisors (33769116).

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

20409372 is a wasteful number, since it uses less digits than its factorization.

20409372 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 347 (or 185 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 27.

The square root of 20409372 is about 4517.6732949606. The cubic root of 20409372 is about 273.2812783414.

Adding to 20409372 its reverse (27390402), we get a palindrome (47799774).

The spelling of 20409372 in words is "twenty million, four hundred nine thousand, three hundred seventy-two".