687654321 has 8 divisors (see below), whose sum is σ = 936380544. Its totient is φ = 448682160.

The previous prime is 687654311. The next prime is 687654329. The reversal of 687654321 is 123456786.

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

It is not a de Polignac number, because 687654321 - 2⁷ = 687654193 is a prime.

It is not an unprimeable number, because it can be changed into a prime (687654329) 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, 2438350 + ... + 2438631.

It is an arithmetic number, because the mean of its divisors is an integer number (117047568).

Almost surely, 2^687654321 is an apocalyptic number.

It is an amenable number.

687654321 is a deficient number, since it is larger than the sum of its proper divisors (248726223).

687654321 is a wasteful number, since it uses less digits than its factorization.

687654321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4877031.

The product of its digits is 241920, while the sum is 42.

The square root of 687654321 is about 26223.1638251375. The cubic root of 687654321 is about 882.6531160893.

The spelling of 687654321 in words is "six hundred eighty-seven million, six hundred fifty-four thousand, three hundred twenty-one".