51609945 has 8 divisors (see below), whose sum is σ = 82575936. Its totient is φ = 27525296.

The previous prime is 51609923. The next prime is 51609973. The reversal of 51609945 is 54990615.

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 51609945 - 2⁵ = 51609913 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1720317 + ... + 1720346.

It is an arithmetic number, because the mean of its divisors is an integer number (10321992).

Almost surely, 2^51609945 is an apocalyptic number.

It is an amenable number.

51609945 is a deficient number, since it is larger than the sum of its proper divisors (30965991).

51609945 is a wasteful number, since it uses less digits than its factorization.

51609945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3440671.

The product of its (nonzero) digits is 48600, while the sum is 39.

The square root of 51609945 is about 7184.0061943180. The cubic root of 51609945 is about 372.3155130470.

The spelling of 51609945 in words is "fifty-one million, six hundred nine thousand, nine hundred forty-five".