131223501 has 6 divisors (see below), whose sum is σ = 189545070. Its totient is φ = 87482328.

The previous prime is 131223461. The next prime is 131223511. The reversal of 131223501 is 105322131.

131223501 is a `hidden beast` number, since 1 + 312 + 2 + 350 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 125216100 + 6007401 = 11190^2 + 2451^2 .

It is not a de Polignac number, because 131223501 - 2⁷ = 131223373 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131223511) by changing a digit.

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 5 ways as a sum of consecutive naturals, for example, 7290186 + ... + 7290203.

It is an arithmetic number, because the mean of its divisors is an integer number (31590845).

Almost surely, 2^131223501 is an apocalyptic number.

It is an amenable number.

131223501 is a deficient number, since it is larger than the sum of its proper divisors (58321569).

131223501 is a wasteful number, since it uses less digits than its factorization.

131223501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14580395 (or 14580392 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 18.

The square root of 131223501 is about 11455.2826678350. The cubic root of 131223501 is about 508.1639748520.

Adding to 131223501 its reverse (105322131), we get a palindrome (236545632).

The spelling of 131223501 in words is "one hundred thirty-one million, two hundred twenty-three thousand, five hundred one".