51205020 has 72 divisors (see below), whose sum is σ = 152355504. Its totient is φ = 12847104.

The previous prime is 51205001. The next prime is 51205027. The reversal of 51205020 is 2050215.

51205020 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51205027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 15864 + ... + 18816.

Almost surely, 2^51205020 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 51205020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (76177752).

51205020 is an abundant number, since it is smaller than the sum of its proper divisors (101150484).

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

51205020 is a wasteful number, since it uses less digits than its factorization.

51205020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2999 (or 2980 counting only the distinct ones).

The product of its (nonzero) digits is 100, while the sum is 15.

The square root of 51205020 is about 7155.7683025654. The cubic root of 51205020 is about 371.3392421132.

Adding to 51205020 its reverse (2050215), we get a palindrome (53255235).

The spelling of 51205020 in words is "fifty-one million, two hundred five thousand, twenty".