205551438651 has 24 divisors (see below), whose sum is σ = 325166128560. Its totient is φ = 124349236416.

The previous prime is 205551438623. The next prime is 205551438667. The reversal of 205551438651 is 156834155502.

205551438651 is a `hidden beast` number, since 2 + 0 + 5 + 5 + 514 + 3 + 86 + 51 = 666.

It is not a de Polignac number, because 205551438651 - 2⁷ = 205551438523 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 205551438597 and 205551438606.

It is not an unprimeable number, because it can be changed into a prime (205551438601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 14881656 + ... + 14895461.

It is an arithmetic number, because the mean of its divisors is an integer number (13548588690).

Almost surely, 2^205551438651 is an apocalyptic number.

205551438651 is a deficient number, since it is larger than the sum of its proper divisors (119614689909).

205551438651 is a wasteful number, since it uses less digits than its factorization.

205551438651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29777195 (or 29777192 counting only the distinct ones).

The product of its (nonzero) digits is 720000, while the sum is 45.

The spelling of 205551438651 in words is "two hundred five billion, five hundred fifty-one million, four hundred thirty-eight thousand, six hundred fifty-one".