20400272 has 40 divisors (see below), whose sum is σ = 42184800. Its totient is φ = 9523712.

The previous prime is 20400271. The next prime is 20400277. The reversal of 20400272 is 27200402.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a self number, because there is not a number n which added to its sum of digits gives 20400272.

It is not an unprimeable number, because it can be changed into a prime (20400271) 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, 48479 + ... + 48897.

It is an arithmetic number, because the mean of its divisors is an integer number (1054620).

Almost surely, 2^20400272 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 20400272, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21092400).

20400272 is an abundant number, since it is smaller than the sum of its proper divisors (21784528).

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

20400272 is a wasteful number, since it uses less digits than its factorization.

20400272 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 623 (or 617 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 17.

The square root of 20400272 is about 4516.6660270602. Note that the first 3 decimals coincide. The cubic root of 20400272 is about 273.2406560016.

Adding to 20400272 its reverse (27200402), we get a palindrome (47600674).

The spelling of 20400272 in words is "twenty million, four hundred thousand, two hundred seventy-two".