51911865 has 12 divisors (see below), whose sum is σ = 89980644. Its totient is φ = 27686304.

The previous prime is 51911807. The next prime is 51911891. The reversal of 51911865 is 56811915.

It can be written as a sum of positive squares in 2 ways, for example, as 41100921 + 10810944 = 6411^2 + 3288^2 .

It is not a de Polignac number, because 51911865 - 2¹³ = 51903673 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 576754 + ... + 576843.

It is an arithmetic number, because the mean of its divisors is an integer number (7498387).

Almost surely, 2^51911865 is an apocalyptic number.

It is an amenable number.

51911865 is a deficient number, since it is larger than the sum of its proper divisors (38068779).

51911865 is a wasteful number, since it uses less digits than its factorization.

51911865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1153608 (or 1153605 counting only the distinct ones).

The product of its digits is 10800, while the sum is 36.

The square root of 51911865 is about 7204.9888965910. The cubic root of 51911865 is about 373.0401215147.

It can be divided in two parts, 5191 and 1865, that added together give a square (7056 = 84²).

The spelling of 51911865 in words is "fifty-one million, nine hundred eleven thousand, eight hundred sixty-five".