51065551 has 4 divisors (see below), whose sum is σ = 51106104. Its totient is φ = 51025000.

The previous prime is 51065533. The next prime is 51065579. The reversal of 51065551 is 15556015.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 51065551 - 2⁷ = 51065423 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51065051) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18325 + ... + 20926.

It is an arithmetic number, because the mean of its divisors is an integer number (12776526).

Almost surely, 2^51065551 is an apocalyptic number.

51065551 is a deficient number, since it is larger than the sum of its proper divisors (40553).

51065551 is a wasteful number, since it uses less digits than its factorization.

51065551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40552.

The product of its (nonzero) digits is 3750, while the sum is 28.

The square root of 51065551 is about 7146.0164427463. The cubic root of 51065551 is about 371.0017920930.

The spelling of 51065551 in words is "fifty-one million, sixty-five thousand, five hundred fifty-one".