201020820 has 192 divisors, whose sum is σ = 755951616. Its totient is φ = 38545920.

The previous prime is 201020789. The next prime is 201020857. The reversal of 201020820 is 28020102.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 201020820.

It is a congruent number.

It is an unprimeable number.

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 63 ways as a sum of consecutive naturals, for example, 58387 + ... + 61733.

It is an arithmetic number, because the mean of its divisors is an integer number (3937248).

Almost surely, 2^201020820 is an apocalyptic number.

201020820 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 201020820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (377975808).

201020820 is an abundant number, since it is smaller than the sum of its proper divisors (554930796).

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

201020820 is a wasteful number, since it uses less digits than its factorization.

201020820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3390 (or 3388 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

The square root of 201020820 is about 14178.1811245307. The cubic root of 201020820 is about 585.7968248882.

Adding to 201020820 its reverse (28020102), we get a palindrome (229040922).

The spelling of 201020820 in words is "two hundred one million, twenty thousand, eight hundred twenty".