51420420 has 60 divisors (see below), whose sum is σ = 161312844. Its totient is φ = 13711680.

The previous prime is 51420419. The next prime is 51420443. The reversal of 51420420 is 2402415.

It can be written as a sum of positive squares in 2 ways, for example, as 27625536 + 23794884 = 5256^2 + 4878^2 .

It is a tau number, because it is divible by the number of its divisors (60).

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

It is a junction number, because it is equal to n+sod(n) for n = 51420393 and 51420402.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 14251 + ... + 17490.

Almost surely, 2^51420420 is an apocalyptic number.

It is an amenable number.

51420420 is an abundant number, since it is smaller than the sum of its proper divisors (109892424).

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

51420420 is a wasteful number, since it uses less digits than its factorization.

51420420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31762 (or 31751 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 18.

The square root of 51420420 is about 7170.8033022807. The cubic root of 51420420 is about 371.8592079069.

Adding to 51420420 its reverse (2402415), we get a palindrome (53822835).

The spelling of 51420420 in words is "fifty-one million, four hundred twenty thousand, four hundred twenty".