685890987 has 4 divisors (see below), whose sum is σ = 914521320. Its totient is φ = 457260656.

The previous prime is 685890949. The next prime is 685891007. The reversal of 685890987 is 789098586.

It is a happy number.

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 685890987 - 2⁶ = 685890923 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 685890987.

It is not an unprimeable number, because it can be changed into a prime (685890917) 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 3 ways as a sum of consecutive naturals, for example, 114315162 + ... + 114315167.

It is an arithmetic number, because the mean of its divisors is an integer number (228630330).

Almost surely, 2^685890987 is an apocalyptic number.

685890987 is a deficient number, since it is larger than the sum of its proper divisors (228630333).

685890987 is a wasteful number, since it uses less digits than its factorization.

685890987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 228630332.

The product of its (nonzero) digits is 8709120, while the sum is 60.

The square root of 685890987 is about 26189.5205568945. The cubic root of 685890987 is about 881.8980155218.

The spelling of 685890987 in words is "six hundred eighty-five million, eight hundred ninety thousand, nine hundred eighty-seven".