51515911 has 4 divisors (see below), whose sum is σ = 51646072. Its totient is φ = 51385752.

The previous prime is 51515869. The next prime is 51515923. The reversal of 51515911 is 11951515.

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 51515911 - 2¹¹ = 51513863 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 51515911.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51515941) 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, 64485 + ... + 65278.

It is an arithmetic number, because the mean of its divisors is an integer number (12911518).

Almost surely, 2^51515911 is an apocalyptic number.

51515911 is a deficient number, since it is larger than the sum of its proper divisors (130161).

51515911 is a wasteful number, since it uses less digits than its factorization.

51515911 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130160.

The product of its digits is 1125, while the sum is 28.

The square root of 51515911 is about 7177.4585334922. The cubic root of 51515911 is about 372.0892543186.

The spelling of 51515911 in words is "fifty-one million, five hundred fifteen thousand, nine hundred eleven".