51021612 has 72 divisors (see below), whose sum is σ = 137337200. Its totient is φ = 15925248.

The previous prime is 51021601. The next prime is 51021637. The reversal of 51021612 is 21612015.

51021612 is a `hidden beast` number, since 51 + 0 + 2 + 1 + 612 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

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 23 ways as a sum of consecutive naturals, for example, 65964 + ... + 66732.

Almost surely, 2^51021612 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 51021612, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (68668600).

51021612 is an abundant number, since it is smaller than the sum of its proper divisors (86315588).

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

51021612 is a wasteful number, since it uses less digits than its factorization.

51021612 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 895 (or 890 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 18.

The square root of 51021612 is about 7142.9414109315. The cubic root of 51021612 is about 370.8953529173.

Adding to 51021612 its reverse (21612015), we get a palindrome (72633627).

It can be divided in two parts, 510 and 21612, that added together give a palindrome (22122).

The spelling of 51021612 in words is "fifty-one million, twenty-one thousand, six hundred twelve".