131613821 has 4 divisors (see below), whose sum is σ = 131660544. Its totient is φ = 131567100.

The previous prime is 131613809. The next prime is 131613827. The reversal of 131613821 is 128316131.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-131613821 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131613827) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18845 + ... + 24866.

It is an arithmetic number, because the mean of its divisors is an integer number (32915136).

Almost surely, 2^131613821 is an apocalyptic number.

It is an amenable number.

131613821 is a deficient number, since it is larger than the sum of its proper divisors (46723).

131613821 is an equidigital number, since it uses as much as digits as its factorization.

131613821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46722.

The product of its digits is 864, while the sum is 26.

The square root of 131613821 is about 11472.3066991778. The cubic root of 131613821 is about 508.6673151507.

Adding to 131613821 its reverse (128316131), we get a palindrome (259929952).

The spelling of 131613821 in words is "one hundred thirty-one million, six hundred thirteen thousand, eight hundred twenty-one".