51509628 has 48 divisors (see below), whose sum is σ = 133932960. Its totient is φ = 17119872.

The previous prime is 51509621. The next prime is 51509629. The reversal of 51509628 is 82690515.

It is a happy number.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 51509592 and 51509601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51509621) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 66250 + ... + 67022.

It is an arithmetic number, because the mean of its divisors is an integer number (2790270).

Almost surely, 2^51509628 is an apocalyptic number.

It is an amenable number.

51509628 is an abundant number, since it is smaller than the sum of its proper divisors (82423332).

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

51509628 is a wasteful number, since it uses less digits than its factorization.

51509628 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1403 (or 1395 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 36.

The square root of 51509628 is about 7177.0208304003. The cubic root of 51509628 is about 372.0741267474.

The spelling of 51509628 in words is "fifty-one million, five hundred nine thousand, six hundred twenty-eight".