51509605 has 8 divisors (see below), whose sum is σ = 70641792. Its totient is φ = 35320848.

The previous prime is 51509599. The next prime is 51509621. The reversal of 51509605 is 50690515.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 51509605 - 2⁷ = 51509477 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 735817 + ... + 735886.

It is an arithmetic number, because the mean of its divisors is an integer number (8830224).

Almost surely, 2^51509605 is an apocalyptic number.

It is an amenable number.

51509605 is a deficient number, since it is larger than the sum of its proper divisors (19132187).

51509605 is a wasteful number, since it uses less digits than its factorization.

51509605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1471715.

The product of its (nonzero) digits is 6750, while the sum is 31.

The square root of 51509605 is about 7177.0192280640. The cubic root of 51509605 is about 372.0740713680.

The spelling of 51509605 in words is "fifty-one million, five hundred nine thousand, six hundred five".