201951 has 12 divisors (see below), whose sum is σ = 307320. Its totient is φ = 127440.

The previous prime is 201947. The next prime is 201953. The reversal of 201951 is 159102.

It is not a de Polignac number, because 201951 - 2² = 201947 is a prime.

201951 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201953) 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, 420 + ... + 761.

It is an arithmetic number, because the mean of its divisors is an integer number (25610).

2²⁰¹⁹⁵¹ is an apocalyptic number.

201951 is a deficient number, since it is larger than the sum of its proper divisors (105369).

201951 is a wasteful number, since it uses less digits than its factorization.

201951 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1206 (or 1203 counting only the distinct ones).

The product of its (nonzero) digits is 90, while the sum is 18.

The square root of 201951 is about 449.3895859942. The cubic root of 201951 is about 58.6698983814.

Subtracting from 201951 its reverse (159102), we obtain a square (42849 = 207²).

The spelling of 201951 in words is "two hundred one thousand, nine hundred fifty-one".