51785881 has 8 divisors (see below), whose sum is σ = 59439744. Its totient is φ = 44196000.

The previous prime is 51785879. The next prime is 51785897. The reversal of 51785881 is 18858715.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 51785881 - 2¹ = 51785879 is a prime.

It is a super-2 number, since 2×51785881² = 5363554941892322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (51785801) 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 7 ways as a sum of consecutive naturals, for example, 14245 + ... + 17506.

It is an arithmetic number, because the mean of its divisors is an integer number (7429968).

Almost surely, 2^51785881 is an apocalyptic number.

It is an amenable number.

51785881 is a deficient number, since it is larger than the sum of its proper divisors (7653863).

51785881 is a wasteful number, since it uses less digits than its factorization.

51785881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31991.

The product of its digits is 89600, while the sum is 43.

The square root of 51785881 is about 7196.2407547274. The cubic root of 51785881 is about 372.7381022055.

The spelling of 51785881 in words is "fifty-one million, seven hundred eighty-five thousand, eight hundred eighty-one".