51384809 has 4 divisors (see below), whose sum is σ = 58725504. Its totient is φ = 44044116.

The previous prime is 51384799. The next prime is 51384857. The reversal of 51384809 is 90848315.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51384809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51384859) 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, 3670337 + ... + 3670350.

It is an arithmetic number, because the mean of its divisors is an integer number (14681376).

Almost surely, 2^51384809 is an apocalyptic number.

It is an amenable number.

51384809 is a deficient number, since it is larger than the sum of its proper divisors (7340695).

51384809 is an equidigital number, since it uses as much as digits as its factorization.

51384809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7340694.

The product of its (nonzero) digits is 34560, while the sum is 38.

The square root of 51384809 is about 7168.3198170841. The cubic root of 51384809 is about 371.7733448951.

The spelling of 51384809 in words is "fifty-one million, three hundred eighty-four thousand, eight hundred nine".