56191321 has 2 divisors, whose sum is σ = 56191322. Its totient is φ = 56191320.

The previous prime is 56191301. The next prime is 56191337. The reversal of 56191321 is 12319165.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 36433296 + 19758025 = 6036^2 + 4445^2 .

It is a cyclic number.

It is not a de Polignac number, because 56191321 - 2⁷ = 56191193 is a prime.

It is equal to p_3349162 and since 56191321 and 3349162 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 56191321.

It is not a weakly prime, because it can be changed into another prime (56191301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28095660 + 28095661.

It is an arithmetic number, because the mean of its divisors is an integer number (28095661).

Almost surely, 2^56191321 is an apocalyptic number.

It is an amenable number.

56191321 is a deficient number, since it is larger than the sum of its proper divisors (1).

56191321 is an equidigital number, since it uses as much as digits as its factorization.

56191321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1620, while the sum is 28.

The square root of 56191321 is about 7496.0870459194. The cubic root of 56191321 is about 383.0214364449.

The spelling of 56191321 in words is "fifty-six million, one hundred ninety-one thousand, three hundred twenty-one".