51820911 has 8 divisors (see below), whose sum is σ = 76771760. Its totient is φ = 34547256.

The previous prime is 51820907. The next prime is 51820927. The reversal of 51820911 is 11902815.

It is not a de Polignac number, because 51820911 - 2² = 51820907 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 1919293 = 51820911 / (5 + 1 + 8 + 2 + 0 + 9 + 1 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51820991) 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, 959620 + ... + 959673.

It is an arithmetic number, because the mean of its divisors is an integer number (9596470).

Almost surely, 2^51820911 is an apocalyptic number.

51820911 is a deficient number, since it is larger than the sum of its proper divisors (24950849).

51820911 is a wasteful number, since it uses less digits than its factorization.

51820911 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1919302 (or 1919296 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 27.

The square root of 51820911 is about 7198.6742529441. The cubic root of 51820911 is about 372.8221281503.

The spelling of 51820911 in words is "fifty-one million, eight hundred twenty thousand, nine hundred eleven".