51642020 has 24 divisors (see below), whose sum is σ = 109447800. Its totient is φ = 20466432.

The previous prime is 51641999. The next prime is 51642029. The reversal of 51642020 is 2024615.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 605284 + 51036736 = 778^2 + 7144^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 51641983 and 51642001.

It is not an unprimeable number, because it can be changed into a prime (51642029) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9665 + ... + 14024.

It is an arithmetic number, because the mean of its divisors is an integer number (4560325).

Almost surely, 2^51642020 is an apocalyptic number.

It is an amenable number.

51642020 is an abundant number, since it is smaller than the sum of its proper divisors (57805780).

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

51642020 is a wasteful number, since it uses less digits than its factorization.

51642020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23807 (or 23805 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 51642020 is about 7186.2382370751. The cubic root of 51642020 is about 372.3926270411.

Adding to 51642020 its reverse (2024615), we get a palindrome (53666635).

The spelling of 51642020 in words is "fifty-one million, six hundred forty-two thousand, twenty".