51121643 has 4 divisors (see below), whose sum is σ = 51334008. Its totient is φ = 50909280.

The previous prime is 51121613. The next prime is 51121649. The reversal of 51121643 is 34612115.

51121643 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 51121643 - 2⁶ = 51121579 is a prime.

It is a super-2 number, since 2×51121643² = 5226844766038898, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51121649) 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, 105821 + ... + 106302.

It is an arithmetic number, because the mean of its divisors is an integer number (12833502).

Almost surely, 2^51121643 is an apocalyptic number.

51121643 is a deficient number, since it is larger than the sum of its proper divisors (212365).

51121643 is a wasteful number, since it uses less digits than its factorization.

51121643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 212364.

The product of its digits is 720, while the sum is 23.

The square root of 51121643 is about 7149.9400696789. The cubic root of 51121643 is about 371.1375823810.

Adding to 51121643 its reverse (34612115), we get a palindrome (85733758).

The spelling of 51121643 in words is "fifty-one million, one hundred twenty-one thousand, six hundred forty-three".