56123021 has 2 divisors, whose sum is σ = 56123022. Its totient is φ = 56123020.

The previous prime is 56123003. The next prime is 56123071. The reversal of 56123021 is 12032165.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 54967396 + 1155625 = 7414^2 + 1075^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-56123021 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 56122984 and 56123002.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (56123071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28061510 + 28061511.

It is an arithmetic number, because the mean of its divisors is an integer number (28061511).

Almost surely, 2^56123021 is an apocalyptic number.

It is an amenable number.

56123021 is a deficient number, since it is larger than the sum of its proper divisors (1).

56123021 is an equidigital number, since it uses as much as digits as its factorization.

56123021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 56123021 is about 7491.5299505508. The cubic root of 56123021 is about 382.8661872592.

Adding to 56123021 its reverse (12032165), we get a palindrome (68155186).

The spelling of 56123021 in words is "fifty-six million, one hundred twenty-three thousand, twenty-one".