1667887661 has 8 divisors (see below), whose sum is σ = 1824319200. Its totient is φ = 1512257040.

The previous prime is 1667887649. The next prime is 1667887693.

1667887661 is nontrivially palindromic in base 10.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1667887661 - 2⁶ = 1667887597 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1667887597 and 1667887606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1667887601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 195866 + ... + 204203.

It is an arithmetic number, because the mean of its divisors is an integer number (228039900).

Almost surely, 2^1667887661 is an apocalyptic number.

1667887661 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1667887661 is a deficient number, since it is larger than the sum of its proper divisors (156431539).

1667887661 is a wasteful number, since it uses less digits than its factorization.

1667887661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 400459.

The product of its digits is 4064256, while the sum is 56.

The square root of 1667887661 is about 40839.7803740422. The cubic root of 1667887661 is about 1185.9205605939.

The spelling of 1667887661 in words is "one billion, six hundred sixty-seven million, eight hundred eighty-seven thousand, six hundred sixty-one".