51817642 has 4 divisors (see below), whose sum is σ = 77726466. Its totient is φ = 25908820.

The previous prime is 51817627. The next prime is 51817681. The reversal of 51817642 is 24671815.

51817642 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 49970761 + 1846881 = 7069^2 + 1359^2 .

It is a junction number, because it is equal to n+sod(n) for n = 51817598 and 51817607.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12954409 + ... + 12954412.

Almost surely, 2^51817642 is an apocalyptic number.

51817642 is a deficient number, since it is larger than the sum of its proper divisors (25908824).

51817642 is a wasteful number, since it uses less digits than its factorization.

51817642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25908823.

The product of its digits is 13440, while the sum is 34.

The square root of 51817642 is about 7198.4471936661. The cubic root of 51817642 is about 372.8142884504.

The spelling of 51817642 in words is "fifty-one million, eight hundred seventeen thousand, six hundred forty-two".