20534436 has 144 divisors (see below), whose sum is σ = 61916400. Its totient is φ = 5677056.

The previous prime is 20534429. The next prime is 20534443. The reversal of 20534436 is 63443502.

20534436 is a nontrivial binomial coefficient, being equal to C(6409, 2).

It is an interprime number because it is at equal distance from previous prime (20534429) and next prime (20534443).

It can be written as a sum of positive squares in 8 ways, for example, as 820836 + 19713600 = 906^2 + 4440^2 .

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 230680 + ... + 230768.

It is an arithmetic number, because the mean of its divisors is an integer number (429975).

Almost surely, 2^20534436 is an apocalyptic number.

20534436 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

20534436 is the 6408-th triangular number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20534436, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30958200).

20534436 is an abundant number, since it is smaller than the sum of its proper divisors (41381964).

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

20534436 is a wasteful number, since it uses less digits than its factorization.

20534436 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 158 (or 153 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 27.

The square root of 20534436 is about 4531.4937934416. The cubic root of 20534436 is about 273.8383439144.

Adding to 20534436 its reverse (63443502), we get a palindrome (83977938).

The spelling of 20534436 in words is "twenty million, five hundred thirty-four thousand, four hundred thirty-six".