1681986667 has 4 divisors (see below), whose sum is σ = 1721102680. Its totient is φ = 1642870656.

The previous prime is 1681986661. The next prime is 1681986673. The reversal of 1681986667 is 7666891861.

It is a happy number.

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

It is an interprime number because it is at equal distance from previous prime (1681986661) and next prime (1681986673).

It is a cyclic number.

It is not a de Polignac number, because 1681986667 - 2⁷ = 1681986539 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1681986661) 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, 19557942 + ... + 19558027.

It is an arithmetic number, because the mean of its divisors is an integer number (430275670).

Almost surely, 2^1681986667 is an apocalyptic number.

1681986667 is a deficient number, since it is larger than the sum of its proper divisors (39116013).

1681986667 is an equidigital number, since it uses as much as digits as its factorization.

1681986667 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39116012.

The product of its digits is 5225472, while the sum is 58.

The square root of 1681986667 is about 41012.0307592784. The cubic root of 1681986667 is about 1189.2528009470.

The spelling of 1681986667 in words is "one billion, six hundred eighty-one million, nine hundred eighty-six thousand, six hundred sixty-seven".