1581609851 has 2 divisors, whose sum is σ = 1581609852. Its totient is φ = 1581609850.

The previous prime is 1581609823. The next prime is 1581609857. The reversal of 1581609851 is 1589061851.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1581609851 - 2¹⁴ = 1581593467 is a prime.

It is not a weakly prime, because it can be changed into another prime (1581609857) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 790804925 + 790804926.

It is an arithmetic number, because the mean of its divisors is an integer number (790804926).

Almost surely, 2^1581609851 is an apocalyptic number.

1581609851 is a deficient number, since it is larger than the sum of its proper divisors (1).

1581609851 is an equidigital number, since it uses as much as digits as its factorization.

1581609851 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 86400, while the sum is 44.

The square root of 1581609851 is about 39769.4587717761. The cubic root of 1581609851 is about 1165.1087229913.

The spelling of 1581609851 in words is "one billion, five hundred eighty-one million, six hundred nine thousand, eight hundred fifty-one".