51489643 has 4 divisors (see below), whose sum is σ = 51508440. Its totient is φ = 51470848.

The previous prime is 51489629. The next prime is 51489649. The reversal of 51489643 is 34698415.

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 51489643 - 2²¹ = 49392491 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 51489596 and 51489605.

It is not an unprimeable number, because it can be changed into a prime (51489649) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4405 + ... + 11062.

It is an arithmetic number, because the mean of its divisors is an integer number (12877110).

Almost surely, 2^51489643 is an apocalyptic number.

51489643 is a deficient number, since it is larger than the sum of its proper divisors (18797).

51489643 is a wasteful number, since it uses less digits than its factorization.

51489643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18796.

The product of its digits is 103680, while the sum is 40.

The square root of 51489643 is about 7175.6284045371. The cubic root of 51489643 is about 372.0260007070.

The spelling of 51489643 in words is "fifty-one million, four hundred eighty-nine thousand, six hundred forty-three".