201401820 has 72 divisors (see below), whose sum is σ = 616687344. Its totient is φ = 53200128.

The previous prime is 201401813. The next prime is 201401861. The reversal of 201401820 is 28104102.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 201401793 and 201401802.

It is a congruent number.

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 23 ways as a sum of consecutive naturals, for example, 14032 + ... + 24488.

It is an arithmetic number, because the mean of its divisors is an integer number (8565102).

Almost surely, 2^201401820 is an apocalyptic number.

201401820 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 201401820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (308343672).

201401820 is an abundant number, since it is smaller than the sum of its proper divisors (415285524).

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

201401820 is a wasteful number, since it uses less digits than its factorization.

201401820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10579 (or 10574 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

The square root of 201401820 is about 14191.6109022197. The cubic root of 201401820 is about 586.1666833163.

Adding to 201401820 its reverse (28104102), we get a palindrome (229505922).

The spelling of 201401820 in words is "two hundred one million, four hundred one thousand, eight hundred twenty".