687921078 has 16 divisors (see below), whose sum is σ = 1481676336. Its totient is φ = 211668000.

The previous prime is 687921067. The next prime is 687921097. The reversal of 687921078 is 870129786.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4409673 + ... + 4409828.

It is an arithmetic number, because the mean of its divisors is an integer number (92604771).

Almost surely, 2^687921078 is an apocalyptic number.

687921078 is an abundant number, since it is smaller than the sum of its proper divisors (793755258).

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

687921078 is a wasteful number, since it uses less digits than its factorization.

687921078 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8819519.

The product of its (nonzero) digits is 338688, while the sum is 48.

The square root of 687921078 is about 26228.2496175402. The cubic root of 687921078 is about 882.7672351802.

The spelling of 687921078 in words is "six hundred eighty-seven million, nine hundred twenty-one thousand, seventy-eight".