20409072 has 20 divisors (see below), whose sum is σ = 52723560. Its totient is φ = 6803008.

The previous prime is 20409041. The next prime is 20409079. The reversal of 20409072 is 27090402.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20409079) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 212547 + ... + 212642.

It is an arithmetic number, because the mean of its divisors is an integer number (2636178).

Almost surely, 2^20409072 is an apocalyptic number.

It is an amenable number.

20409072 is an abundant number, since it is smaller than the sum of its proper divisors (32314488).

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

20409072 is a wasteful number, since it uses less digits than its factorization.

20409072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 425200 (or 425194 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 24.

The square root of 20409072 is about 4517.6400919064. The cubic root of 20409072 is about 273.2799393358.

Adding to 20409072 its reverse (27090402), we get a palindrome (47499474).

The spelling of 20409072 in words is "twenty million, four hundred nine thousand, seventy-two".