1666925587 has 2 divisors, whose sum is σ = 1666925588. Its totient is φ = 1666925586.

The previous prime is 1666925567. The next prime is 1666925639. The reversal of 1666925587 is 7855296661.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1666925587 is a prime.

It is not a weakly prime, because it can be changed into another prime (1666925567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 833462793 + 833462794.

It is an arithmetic number, because the mean of its divisors is an integer number (833462794).

Almost surely, 2^1666925587 is an apocalyptic number.

1666925587 is a deficient number, since it is larger than the sum of its proper divisors (1).

1666925587 is an equidigital number, since it uses as much as digits as its factorization.

1666925587 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5443200, while the sum is 55.

The square root of 1666925587 is about 40828.0000367395. Note that the first 4 decimals coincide. The cubic root of 1666925587 is about 1185.6924951176.

The spelling of 1666925587 in words is "one billion, six hundred sixty-six million, nine hundred twenty-five thousand, five hundred eighty-seven".