56751781 has 2 divisors, whose sum is σ = 56751782. Its totient is φ = 56751780.

The previous prime is 56751767. The next prime is 56751857. The reversal of 56751781 is 18715765.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 42380100 + 14371681 = 6510^2 + 3791^2 .

It is a cyclic number.

It is not a de Polignac number, because 56751781 - 2¹¹ = 56749733 is a prime.

It is a super-2 number, since 2×56751781² = 6441529293343922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (56701781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28375890 + 28375891.

It is an arithmetic number, because the mean of its divisors is an integer number (28375891).

Almost surely, 2^56751781 is an apocalyptic number.

It is an amenable number.

56751781 is a deficient number, since it is larger than the sum of its proper divisors (1).

56751781 is an equidigital number, since it uses as much as digits as its factorization.

56751781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 58800, while the sum is 40.

The square root of 56751781 is about 7533.3777948540. The cubic root of 56751781 is about 384.2906621846.

The spelling of 56751781 in words is "fifty-six million, seven hundred fifty-one thousand, seven hundred eighty-one".