1667633985 has 24 divisors (see below), whose sum is σ = 2891799144. Its totient is φ = 889025280.

The previous prime is 1667633983. The next prime is 1667634071. The reversal of 1667633985 is 5893367661.

1667633985 is a `hidden beast` number, since 166 + 76 + 339 + 85 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 21790224 + 1645843761 = 4668^2 + 40569^2 .

It is not a de Polignac number, because 1667633985 - 2¹ = 1667633983 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1667633983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 122269 + ... + 135221.

It is an arithmetic number, because the mean of its divisors is an integer number (120491631).

Almost surely, 2^1667633985 is an apocalyptic number.

1667633985 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1667633985 is a deficient number, since it is larger than the sum of its proper divisors (1224165159).

1667633985 is a wasteful number, since it uses less digits than its factorization.

1667633985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15825 (or 15822 counting only the distinct ones).

The product of its digits is 4898880, while the sum is 54.

The square root of 1667633985 is about 40836.6745095631. The cubic root of 1667633985 is about 1185.8604336752.

The spelling of 1667633985 in words is "one billion, six hundred sixty-seven million, six hundred thirty-three thousand, nine hundred eighty-five".