56131821 has 24 divisors (see below), whose sum is σ = 82738656. Its totient is φ = 36663840.

The previous prime is 56131811. The next prime is 56131847. The reversal of 56131821 is 12813165.

It is not a de Polignac number, because 56131821 - 2⁷ = 56131693 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (56131811) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 121531 + ... + 121991.

It is an arithmetic number, because the mean of its divisors is an integer number (3447444).

Almost surely, 2^56131821 is an apocalyptic number.

It is an amenable number.

56131821 is a deficient number, since it is larger than the sum of its proper divisors (26606835).

56131821 is a wasteful number, since it uses less digits than its factorization.

56131821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 713 (or 710 counting only the distinct ones).

The product of its digits is 1440, while the sum is 27.

The square root of 56131821 is about 7492.1172574914. The cubic root of 56131821 is about 382.8861971488.

Adding to 56131821 its reverse (12813165), we get a palindrome (68944986).

The spelling of 56131821 in words is "fifty-six million, one hundred thirty-one thousand, eight hundred twenty-one".