1667216687 has 4 divisors (see below), whose sum is σ = 1667567616. Its totient is φ = 1666865760.

The previous prime is 1667216669. The next prime is 1667216717. The reversal of 1667216687 is 7866127661.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1667216687 - 2⁶ = 1667216623 is a prime.

It is a super-2 number, since 2×1667216687² = 5559222962822511938, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1667216647) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 168239 + ... + 177872.

It is an arithmetic number, because the mean of its divisors is an integer number (416891904).

Almost surely, 2^1667216687 is an apocalyptic number.

1667216687 is a deficient number, since it is larger than the sum of its proper divisors (350929).

1667216687 is an equidigital number, since it uses as much as digits as its factorization.

1667216687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 350928.

The product of its digits is 1016064, while the sum is 50.

The square root of 1667216687 is about 40831.5648365330. The cubic root of 1667216687 is about 1185.7615113949.

The spelling of 1667216687 in words is "one billion, six hundred sixty-seven million, two hundred sixteen thousand, six hundred eighty-seven".