51021040020 has 96 divisors (see below), whose sum is σ = 145072599168. Its totient is φ = 13395013632.

The previous prime is 51021040013. The next prime is 51021040123. The reversal of 51021040020 is 2004012015.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 13798812 + ... + 13802508.

It is an arithmetic number, because the mean of its divisors is an integer number (1511172908).

Almost surely, 2^51021040020 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 51021040020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (72536299584).

51021040020 is an abundant number, since it is smaller than the sum of its proper divisors (94051559148).

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

51021040020 is a wasteful number, since it uses less digits than its factorization.

51021040020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7209 (or 7207 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 15.

Adding to 51021040020 its reverse (2004012015), we get a palindrome (53025052035).

The spelling of 51021040020 in words is "fifty-one billion, twenty-one million, forty thousand, twenty".