51815651 has 4 divisors (see below), whose sum is σ = 53216112. Its totient is φ = 50415192.

The previous prime is 51815639. The next prime is 51815671. The reversal of 51815651 is 15651815.

51815651 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 is a cyclic number.

It is not a de Polignac number, because 51815651 - 2¹⁸ = 51553507 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51815671) by changing a digit.

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 in 3 ways as a sum of consecutive naturals, for example, 700175 + ... + 700248.

It is an arithmetic number, because the mean of its divisors is an integer number (13304028).

Almost surely, 2^51815651 is an apocalyptic number.

51815651 is a deficient number, since it is larger than the sum of its proper divisors (1400461).

51815651 is a wasteful number, since it uses less digits than its factorization.

51815651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1400460.

The product of its digits is 6000, while the sum is 32.

The square root of 51815651 is about 7198.3088986233. The cubic root of 51815651 is about 372.8095134824.

The spelling of 51815651 in words is "fifty-one million, eight hundred fifteen thousand, six hundred fifty-one".