51775581 has 16 divisors (see below), whose sum is σ = 81103680. Its totient is φ = 28965120.

The previous prime is 51775567. The next prime is 51775609. The reversal of 51775581 is 18557715.

It is a happy number.

It is not a de Polignac number, because 51775581 - 2⁷ = 51775453 is a prime.

It is a super-2 number, since 2×51775581² = 5361421575775122, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51775501) 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 15 ways as a sum of consecutive naturals, for example, 59916 + ... + 60773.

It is an arithmetic number, because the mean of its divisors is an integer number (5068980).

Almost surely, 2^51775581 is an apocalyptic number.

It is an amenable number.

51775581 is a deficient number, since it is larger than the sum of its proper divisors (29328099).

51775581 is a wasteful number, since it uses less digits than its factorization.

51775581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120716.

The product of its digits is 49000, while the sum is 39.

The square root of 51775581 is about 7195.5250677070. The cubic root of 51775581 is about 372.7133885388.

The spelling of 51775581 in words is "fifty-one million, seven hundred seventy-five thousand, five hundred eighty-one".