51565551 has 8 divisors (see below), whose sum is σ = 69192624. Its totient is φ = 34157760.

The previous prime is 51565543. The next prime is 51565571. The reversal of 51565551 is 15556515.

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

It is not a de Polignac number, because 51565551 - 2³ = 51565543 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51565511) 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, 54270 + ... + 55211.

It is an arithmetic number, because the mean of its divisors is an integer number (8649078).

Almost surely, 2^51565551 is an apocalyptic number.

51565551 is a deficient number, since it is larger than the sum of its proper divisors (17627073).

51565551 is a wasteful number, since it uses less digits than its factorization.

51565551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109641.

The product of its digits is 18750, while the sum is 33.

The square root of 51565551 is about 7180.9157494013. The cubic root of 51565551 is about 372.2087292585.

It can be divided in two parts, 515 and 65551, that added together give a palindrome (66066).

The spelling of 51565551 in words is "fifty-one million, five hundred sixty-five thousand, five hundred fifty-one".