51320811 has 4 divisors (see below), whose sum is σ = 68427752. Its totient is φ = 34213872.

The previous prime is 51320803. The next prime is 51320837. The reversal of 51320811 is 11802315.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 51320811 - 2³ = 51320803 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51320411) 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, 8553466 + ... + 8553471.

It is an arithmetic number, because the mean of its divisors is an integer number (17106938).

Almost surely, 2^51320811 is an apocalyptic number.

51320811 is a deficient number, since it is larger than the sum of its proper divisors (17106941).

51320811 is a wasteful number, since it uses less digits than its factorization.

51320811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17106940.

The product of its (nonzero) digits is 240, while the sum is 21.

The square root of 51320811 is about 7163.8544792591. The cubic root of 51320811 is about 371.6189371657.

The spelling of 51320811 in words is "fifty-one million, three hundred twenty thousand, eight hundred eleven".