51801765 has 8 divisors (see below), whose sum is σ = 82882848. Its totient is φ = 27627600.

The previous prime is 51801731. The next prime is 51801767. The reversal of 51801765 is 56710815.

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

It is not a de Polignac number, because 51801765 - 2⁷ = 51801637 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51801767) 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, 1726711 + ... + 1726740.

It is an arithmetic number, because the mean of its divisors is an integer number (10360356).

Almost surely, 2^51801765 is an apocalyptic number.

It is an amenable number.

51801765 is a deficient number, since it is larger than the sum of its proper divisors (31081083).

51801765 is a wasteful number, since it uses less digits than its factorization.

51801765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3453459.

The product of its (nonzero) digits is 8400, while the sum is 33.

The square root of 51801765 is about 7197.3443018936. The cubic root of 51801765 is about 372.7762076162.

The spelling of 51801765 in words is "fifty-one million, eight hundred one thousand, seven hundred sixty-five".