689767987 has 4 divisors (see below), whose sum is σ = 713553120. Its totient is φ = 665982856.

The previous prime is 689767951. The next prime is 689767993. The reversal of 689767987 is 789767986.

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 689767987 - 2²³ = 681379379 is a prime.

It is a super-3 number, since 3×689767987³ (a number of 27 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (689767927) 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 3 ways as a sum of consecutive naturals, for example, 11892523 + ... + 11892580.

It is an arithmetic number, because the mean of its divisors is an integer number (178388280).

Almost surely, 2^689767987 is an apocalyptic number.

689767987 is a deficient number, since it is larger than the sum of its proper divisors (23785133).

689767987 is a wasteful number, since it uses less digits than its factorization.

689767987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23785132.

The product of its digits is 64012032, while the sum is 67.

The square root of 689767987 is about 26263.4344098406. The cubic root of 689767987 is about 883.5565378594.

Subtracting 689767987 from its reverse (789767986), we obtain a palindrome (99999999).

The spelling of 689767987 in words is "six hundred eighty-nine million, seven hundred sixty-seven thousand, nine hundred eighty-seven".