20356240 has 40 divisors (see below), whose sum is σ = 48231288. Its totient is φ = 7987200.

The previous prime is 20356229. The next prime is 20356241. The reversal of 20356240 is 4265302.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 4260096 + 16096144 = 2064^2 + 4012^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is not an unprimeable number, because it can be changed into a prime (20356241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1840 + ... + 6640.

Almost surely, 2^20356240 is an apocalyptic number.

20356240 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 20356240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24115644).

20356240 is an abundant number, since it is smaller than the sum of its proper divisors (27875048).

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

20356240 is a wasteful number, since it uses less digits than its factorization.

20356240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4867 (or 4861 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 22.

The square root of 20356240 is about 4511.7890021587. The cubic root of 20356240 is about 273.0439266130.

The spelling of 20356240 in words is "twenty million, three hundred fifty-six thousand, two hundred forty".