51021823 has 4 divisors (see below), whose sum is σ = 51061600. Its totient is φ = 50982048.

The previous prime is 51021793. The next prime is 51021827. The reversal of 51021823 is 32812015.

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 51021823 - 2¹⁷ = 50890751 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 51021794 and 51021803.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51021827) 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, 17898 + ... + 20551.

It is an arithmetic number, because the mean of its divisors is an integer number (12765400).

Almost surely, 2^51021823 is an apocalyptic number.

51021823 is a deficient number, since it is larger than the sum of its proper divisors (39777).

51021823 is a wasteful number, since it uses less digits than its factorization.

51021823 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39776.

The product of its (nonzero) digits is 480, while the sum is 22.

The square root of 51021823 is about 7142.9561807420. The cubic root of 51021823 is about 370.8958641961.

Adding to 51021823 its reverse (32812015), we get a palindrome (83833838).

The spelling of 51021823 in words is "fifty-one million, twenty-one thousand, eight hundred twenty-three".