56523781 has 2 divisors, whose sum is σ = 56523782. Its totient is φ = 56523780.

The previous prime is 56523773. The next prime is 56523787. The reversal of 56523781 is 18732565.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 35593156 + 20930625 = 5966^2 + 4575^2 .

It is a cyclic number.

It is not a de Polignac number, because 56523781 - 2³ = 56523773 is a prime.

It is a super-2 number, since 2×56523781² = 6389875637071922, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 56523781.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (56523787) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28261890 + 28261891.

It is an arithmetic number, because the mean of its divisors is an integer number (28261891).

Almost surely, 2^56523781 is an apocalyptic number.

It is an amenable number.

56523781 is a deficient number, since it is larger than the sum of its proper divisors (1).

56523781 is an equidigital number, since it uses as much as digits as its factorization.

56523781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 50400, while the sum is 37.

The square root of 56523781 is about 7518.2299113555. The cubic root of 56523781 is about 383.7753428569.

The spelling of 56523781 in words is "fifty-six million, five hundred twenty-three thousand, seven hundred eighty-one".