685998719 has 8 divisors (see below), whose sum is σ = 787979808. Its totient is φ = 585012960.

The previous prime is 685998707. The next prime is 685998751. The reversal of 685998719 is 917899586.

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

It is not a de Polignac number, because 685998719 - 2²⁴ = 669221503 is a prime.

It is a super-2 number, since 2×685998719² = 941188484939281922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (685998119) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 247352 + ... + 250109.

It is an arithmetic number, because the mean of its divisors is an integer number (98497476).

Almost surely, 2^685998719 is an apocalyptic number.

685998719 is a deficient number, since it is larger than the sum of its proper divisors (101981089).

685998719 is a wasteful number, since it uses less digits than its factorization.

685998719 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 497665.

The product of its digits is 9797760, while the sum is 62.

The square root of 685998719 is about 26191.5772530025. The cubic root of 685998719 is about 881.9441859605.

The spelling of 685998719 in words is "six hundred eighty-five million, nine hundred ninety-eight thousand, seven hundred nineteen".