686249984 has 48 divisors (see below), whose sum is σ = 1568221200. Its totient is φ = 294100992.

The previous prime is 686249981. The next prime is 686249987. The reversal of 686249984 is 489942686.

It is an interprime number because it is at equal distance from previous prime (686249981) and next prime (686249987).

It is a Harshad number since it is a multiple of its sum of digits (56).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (686249981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9599 + ... + 38270.

It is an arithmetic number, because the mean of its divisors is an integer number (32671275).

Almost surely, 2^686249984 is an apocalyptic number.

686249984 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

686249984 is an abundant number, since it is smaller than the sum of its proper divisors (881971216).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

686249984 is an equidigital number, since it uses as much as digits as its factorization.

686249984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47898 (or 47878 counting only the distinct ones).

The product of its digits is 5971968, while the sum is 56.

The square root of 686249984 is about 26196.3734894737. The cubic root of 686249984 is about 882.0518512031.

The spelling of 686249984 in words is "six hundred eighty-six million, two hundred forty-nine thousand, nine hundred eighty-four".