131023221 has 16 divisors (see below), whose sum is σ = 210163200. Its totient is φ = 70929648.

The previous prime is 131023163. The next prime is 131023223. The reversal of 131023221 is 122320131.

It is not a de Polignac number, because 131023221 - 2²² = 126828917 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 131023221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131023223) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 163791 + ... + 164588.

It is an arithmetic number, because the mean of its divisors is an integer number (13135200).

Almost surely, 2^131023221 is an apocalyptic number.

It is an amenable number.

131023221 is a deficient number, since it is larger than the sum of its proper divisors (79139979).

131023221 is a wasteful number, since it uses less digits than its factorization.

131023221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 328408.

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 131023221 is about 11446.5375114049. The cubic root of 131023221 is about 507.9053146218.

Adding to 131023221 its reverse (122320131), we get a palindrome (253343352).

It can be divided in two parts, 1310 and 23221, that added together give a triangular number (24531 = T₂₂₁).

The spelling of 131023221 in words is "one hundred thirty-one million, twenty-three thousand, two hundred twenty-one".