51021004240 has 40 divisors (see below), whose sum is σ = 118648912680. Its totient is φ = 20404087296.

The previous prime is 51021004219. The next prime is 51021004253. The reversal of 51021004240 is 4240012015.

It can be written as a sum of positive squares in 4 ways, for example, as 25250481216 + 25770523024 = 158904^2 + 160532^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 327762 + ... + 457678.

It is an arithmetic number, because the mean of its divisors is an integer number (2966222817).

Almost surely, 2^51021004240 is an apocalyptic number.

It is an amenable number.

51021004240 is an abundant number, since it is smaller than the sum of its proper divisors (67627908440).

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

51021004240 is a wasteful number, since it uses less digits than its factorization.

51021004240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 134839 (or 134833 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 19.

Adding to 51021004240 its reverse (4240012015), we get a palindrome (55261016255).

The spelling of 51021004240 in words is "fifty-one billion, twenty-one million, four thousand, two hundred forty".