684865491 has 16 divisors (see below), whose sum is σ = 930892800. Its totient is φ = 447768288.

The previous prime is 684865459. The next prime is 684865499. The reversal of 684865491 is 194568486.

It is not a de Polignac number, because 684865491 - 2⁵ = 684865459 is a prime.

It is a super-3 number, since 3×684865491³ (a number of 27 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (684865499) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38590 + ... + 53468.

It is an arithmetic number, because the mean of its divisors is an integer number (58180800).

Almost surely, 2^684865491 is an apocalyptic number.

684865491 is a deficient number, since it is larger than the sum of its proper divisors (246027309).

684865491 is a wasteful number, since it uses less digits than its factorization.

684865491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15178.

The product of its digits is 1658880, while the sum is 51.

The square root of 684865491 is about 26169.9348680886. The cubic root of 684865491 is about 881.4582789833.

The spelling of 684865491 in words is "six hundred eighty-four million, eight hundred sixty-five thousand, four hundred ninety-one".