51123820 has 24 divisors (see below), whose sum is σ = 117120528. Its totient is φ = 18590400.

The previous prime is 51123817. The next prime is 51123833. The reversal of 51123820 is 2832115.

It is a super-2 number, since 2×51123820² = 5227289942784800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a junction number, because it is equal to n+sod(n) for n = 51123791 and 51123800.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 115971 + ... + 116410.

It is an arithmetic number, because the mean of its divisors is an integer number (4880022).

Almost surely, 2^51123820 is an apocalyptic number.

It is an amenable number.

51123820 is an abundant number, since it is smaller than the sum of its proper divisors (65996708).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

51123820 is a wasteful number, since it uses less digits than its factorization.

51123820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 232401 (or 232399 counting only the distinct ones).

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

The square root of 51123820 is about 7150.0923070965. The cubic root of 51123820 is about 371.1428505675.

Adding to 51123820 its reverse (2832115), we get a palindrome (53955935).

The spelling of 51123820 in words is "fifty-one million, one hundred twenty-three thousand, eight hundred twenty".