51305551 has 4 divisors (see below), whose sum is σ = 55969704. Its totient is φ = 46641400.

The previous prime is 51305539. The next prime is 51305591. The reversal of 51305551 is 15550315.

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 51305551 - 2¹¹ = 51303503 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 (51305521) 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, 2332060 + ... + 2332081.

It is an arithmetic number, because the mean of its divisors is an integer number (13992426).

Almost surely, 2^51305551 is an apocalyptic number.

51305551 is a deficient number, since it is larger than the sum of its proper divisors (4664153).

51305551 is a wasteful number, since it uses less digits than its factorization.

51305551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4664152.

The product of its (nonzero) digits is 1875, while the sum is 25.

The square root of 51305551 is about 7162.7893309799. The cubic root of 51305551 is about 371.5821004710.

Adding to 51305551 its reverse (15550315), we get a palindrome (66855866).

The spelling of 51305551 in words is "fifty-one million, three hundred five thousand, five hundred fifty-one".