656421131 has 4 divisors (see below), whose sum is σ = 656484600. Its totient is φ = 656357664.

The previous prime is 656421113. The next prime is 656421133. The reversal of 656421131 is 131124656.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 656421131 - 2²⁶ = 589312267 is a prime.

It is a super-3 number, since 3×656421131³ (a number of 27 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 656421094 and 656421103.

It is not an unprimeable number, because it can be changed into a prime (656421133) 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 3 ways as a sum of consecutive naturals, for example, 12221 + ... + 38238.

It is an arithmetic number, because the mean of its divisors is an integer number (164121150).

Almost surely, 2^656421131 is an apocalyptic number.

656421131 is a deficient number, since it is larger than the sum of its proper divisors (63469).

656421131 is a wasteful number, since it uses less digits than its factorization.

656421131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63468.

The product of its digits is 4320, while the sum is 29.

The square root of 656421131 is about 25620.7168322824. The cubic root of 656421131 is about 869.0821919157.

Adding to 656421131 its reverse (131124656), we get a palindrome (787545787).

The spelling of 656421131 in words is "six hundred fifty-six million, four hundred twenty-one thousand, one hundred thirty-one".