51731565 has 8 divisors (see below), whose sum is σ = 82770528. Its totient is φ = 27590160.

The previous prime is 51731549. The next prime is 51731569. The reversal of 51731565 is 56513715.

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

It is not a de Polignac number, because 51731565 - 2⁴ = 51731549 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51731569) 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, 1724371 + ... + 1724400.

It is an arithmetic number, because the mean of its divisors is an integer number (10346316).

Almost surely, 2^51731565 is an apocalyptic number.

It is an amenable number.

51731565 is a deficient number, since it is larger than the sum of its proper divisors (31038963).

51731565 is a wasteful number, since it uses less digits than its factorization.

51731565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3448779.

The product of its digits is 15750, while the sum is 33.

The square root of 51731565 is about 7192.4658497625. The cubic root of 51731565 is about 372.6077402564.

The spelling of 51731565 in words is "fifty-one million, seven hundred thirty-one thousand, five hundred sixty-five".