51420020 has 12 divisors (see below), whose sum is σ = 107982084. Its totient is φ = 20568000.

The previous prime is 51420013. The next prime is 51420029. The reversal of 51420020 is 2002415.

It can be written as a sum of positive squares in 2 ways, for example, as 10995856 + 40424164 = 3316^2 + 6358^2 .

It is a junction number, because it is equal to n+sod(n) for n = 51419977 and 51420004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51420029) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1285481 + ... + 1285520.

It is an arithmetic number, because the mean of its divisors is an integer number (8998507).

Almost surely, 2^51420020 is an apocalyptic number.

It is an amenable number.

51420020 is an abundant number, since it is smaller than the sum of its proper divisors (56562064).

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

51420020 is a wasteful number, since it uses less digits than its factorization.

51420020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2571010 (or 2571008 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 14.

The square root of 51420020 is about 7170.7754113485. The cubic root of 51420020 is about 371.8582436722.

Adding to 51420020 its reverse (2002415), we get a palindrome (53422435).

The spelling of 51420020 in words is "fifty-one million, four hundred twenty thousand, twenty".