51605111 has 4 divisors (see below), whose sum is σ = 53269824. Its totient is φ = 49940400.

The previous prime is 51605063. The next prime is 51605131. The reversal of 51605111 is 11150615.

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 51605111 - 2¹⁰ = 51604087 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 (51605131) 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, 832310 + ... + 832371.

It is an arithmetic number, because the mean of its divisors is an integer number (13317456).

Almost surely, 2^51605111 is an apocalyptic number.

51605111 is a deficient number, since it is larger than the sum of its proper divisors (1664713).

51605111 is a wasteful number, since it uses less digits than its factorization.

51605111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1664712.

The product of its (nonzero) digits is 150, while the sum is 20.

The square root of 51605111 is about 7183.6697446361. The cubic root of 51605111 is about 372.3038884826.

Adding to 51605111 its reverse (11150615), we get a palindrome (62755726).

The spelling of 51605111 in words is "fifty-one million, six hundred five thousand, one hundred eleven".