51381779 has 4 divisors (see below), whose sum is σ = 51420576. Its totient is φ = 51342984.

The previous prime is 51381749. The next prime is 51381797. The reversal of 51381779 is 97718315.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 97718315 = 5 ⋅19543663.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51381779 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51381709) 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, 17339 + ... + 20084.

It is an arithmetic number, because the mean of its divisors is an integer number (12855144).

Almost surely, 2^51381779 is an apocalyptic number.

51381779 is a deficient number, since it is larger than the sum of its proper divisors (38797).

51381779 is a wasteful number, since it uses less digits than its factorization.

51381779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38796.

The product of its digits is 52920, while the sum is 41.

The square root of 51381779 is about 7168.1084673713. The cubic root of 51381779 is about 371.7660373179.

The spelling of 51381779 in words is "fifty-one million, three hundred eighty-one thousand, seven hundred seventy-nine".