201531806 has 24 divisors (see below), whose sum is σ = 363001536. Its totient is φ = 83583360.

The previous prime is 201531793. The next prime is 201531809. The reversal of 201531806 is 608135102.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201531809) 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 11 ways as a sum of consecutive naturals, for example, 30131 + ... + 36206.

It is an arithmetic number, because the mean of its divisors is an integer number (15125064).

Almost surely, 2^201531806 is an apocalyptic number.

201531806 is a deficient number, since it is larger than the sum of its proper divisors (161469730).

201531806 is a wasteful number, since it uses less digits than its factorization.

201531806 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66384 (or 66377 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 201531806 is about 14196.1898409397. The cubic root of 201531806 is about 586.2927614164.

Adding to 201531806 its reverse (608135102), we get a palindrome (809666908).

The spelling of 201531806 in words is "two hundred one million, five hundred thirty-one thousand, eight hundred six".