51021312 has 80 divisors (see below), whose sum is σ = 138473280. Its totient is φ = 16689152.

The previous prime is 51021307. The next prime is 51021323. The reversal of 51021312 is 21312015.

It is a junction number, because it is equal to n+sod(n) for n = 51021291 and 51021300.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 90343 + ... + 90905.

It is an arithmetic number, because the mean of its divisors is an integer number (1730916).

Almost surely, 2^51021312 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51021312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (69236640).

51021312 is an abundant number, since it is smaller than the sum of its proper divisors (87451968).

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

51021312 is an equidigital number, since it uses as much as digits as its factorization.

51021312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 643 (or 627 counting only the distinct ones).

The product of its (nonzero) digits is 60, while the sum is 15.

The square root of 51021312 is about 7142.9204111484. The cubic root of 51021312 is about 370.8946259781.

Adding to 51021312 its reverse (21312015), we get a palindrome (72333327).

The spelling of 51021312 in words is "fifty-one million, twenty-one thousand, three hundred twelve".