51990067447 has 4 divisors (see below), whose sum is σ = 52309025080. Its totient is φ = 51671109816.

The previous prime is 51990067439. The next prime is 51990067487. The reversal of 51990067447 is 74476009915.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 74476009915 = 5 ⋅14895201983.

It is a cyclic number.

It is not a de Polignac number, because 51990067447 - 2³ = 51990067439 is a prime.

It is a super-2 number, since 2×51990067447² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 51990067394 and 51990067403.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51990067417) 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, 159478572 + ... + 159478897.

It is an arithmetic number, because the mean of its divisors is an integer number (13077256270).

Almost surely, 2^51990067447 is an apocalyptic number.

51990067447 is a deficient number, since it is larger than the sum of its proper divisors (318957633).

51990067447 is a wasteful number, since it uses less digits than its factorization.

51990067447 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 318957632.

The product of its (nonzero) digits is 1905120, while the sum is 52.

The spelling of 51990067447 in words is "fifty-one billion, nine hundred ninety million, sixty-seven thousand, four hundred forty-seven".