51530211723861 has 160 divisors (see below), whose sum is σ = 92563920408960. Its totient is φ = 28222941487104.

The previous prime is 51530211723829. The next prime is 51530211723869. The reversal of 51530211723861 is 16832711203515.

51530211723861 is a `hidden beast` number, since 5 + 1 + 53 + 0 + 211 + 7 + 2 + 386 + 1 = 666.

It is not a de Polignac number, because 51530211723861 - 2⁵ = 51530211723829 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51530211723869) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 185906605 + ... + 186183581.

It is an arithmetic number, because the mean of its divisors is an integer number (578524502556).

Almost surely, 2^{51530211723861} is an apocalyptic number.

51530211723861 is a gapful number since it is divisible by the number (51) formed by its first and last digit.

It is an amenable number.

51530211723861 is a deficient number, since it is larger than the sum of its proper divisors (41033708685099).

51530211723861 is a wasteful number, since it uses less digits than its factorization.

51530211723861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 277585 (or 277576 counting only the distinct ones).

The product of its (nonzero) digits is 302400, while the sum is 45.

The spelling of 51530211723861 in words is "fifty-one trillion, five hundred thirty billion, two hundred eleven million, seven hundred twenty-three thousand, eight hundred sixty-one".