51505811 has 6 divisors (see below), whose sum is σ = 59914980. Its totient is φ = 44147796.

The previous prime is 51505759. The next prime is 51505823. The reversal of 51505811 is 11850515.

51505811 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 51505811 - 2¹⁰ = 51504787 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51505511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 525521 + ... + 525618.

It is an arithmetic number, because the mean of its divisors is an integer number (9985830).

Almost surely, 2^51505811 is an apocalyptic number.

51505811 is a deficient number, since it is larger than the sum of its proper divisors (8409169).

51505811 is a wasteful number, since it uses less digits than its factorization.

51505811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1051153 (or 1051146 counting only the distinct ones).

The product of its (nonzero) digits is 1000, while the sum is 26.

The square root of 51505811 is about 7176.7549073380. The cubic root of 51505811 is about 372.0649359606.

The spelling of 51505811 in words is "fifty-one million, five hundred five thousand, eight hundred eleven".