51016550581 has 4 divisors (see below), whose sum is σ = 52102009152. Its totient is φ = 49931092012.

The previous prime is 51016550509. The next prime is 51016550617. The reversal of 51016550581 is 18505561015.

It is a happy number.

51016550581 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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, and also an emirpimes, since its reverse is a distinct semiprime: 18505561015 = 5 ⋅3701112203.

It is a cyclic number.

It is not a de Polignac number, because 51016550581 - 2¹³ = 51016542389 is a prime.

It is a super-2 number, since 2×51016550581² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 51016550581.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51016550881) 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, 542729215 + ... + 542729308.

It is an arithmetic number, because the mean of its divisors is an integer number (13025502288).

Almost surely, 2^51016550581 is an apocalyptic number.

It is an amenable number.

51016550581 is a deficient number, since it is larger than the sum of its proper divisors (1085458571).

51016550581 is a wasteful number, since it uses less digits than its factorization.

51016550581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1085458570.

The product of its (nonzero) digits is 30000, while the sum is 37.

The spelling of 51016550581 in words is "fifty-one billion, sixteen million, five hundred fifty thousand, five hundred eighty-one".