20406250 has 28 divisors (see below), whose sum is σ = 38319822. Its totient is φ = 8150000.

The previous prime is 20406229. The next prime is 20406259. The reversal of 20406250 is 5260402.

It can be written as a sum of positive squares in 7 ways, for example, as 13682601 + 6723649 = 3699^2 + 2593^2 .

It is not an unprimeable number, because it can be changed into a prime (20406259) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 30924 + ... + 31576.

Almost surely, 2^20406250 is an apocalyptic number.

20406250 is a deficient number, since it is larger than the sum of its proper divisors (17913572).

20406250 is an frugal number, since it uses more digits than its factorization.

20406250 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 685 (or 660 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 19.

The square root of 20406250 is about 4517.3277498982. The cubic root of 20406250 is about 273.2673431150.

Adding to 20406250 its reverse (5260402), we get a palindrome (25666652).

The spelling of 20406250 in words is "twenty million, four hundred six thousand, two hundred fifty".