687156840 has 48 divisors (see below), whose sum is σ = 2233260900. Its totient is φ = 183241728.

The previous prime is 687156829. The next prime is 687156853. The reversal of 687156840 is 48651786.

It is a happy number.

687156840 is a `hidden beast` number, since 6 + 87 + 1 + 568 + 4 + 0 = 666.

687156840 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 680896836 + 6260004 = 26094^2 + 2502^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 954025 + ... + 954744.

Almost surely, 2^687156840 is an apocalyptic number.

687156840 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

687156840 is an abundant number, since it is smaller than the sum of its proper divisors (1546104060).

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

687156840 is a wasteful number, since it uses less digits than its factorization.

687156840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1908786 (or 1908779 counting only the distinct ones).

The product of its (nonzero) digits is 322560, while the sum is 45.

The square root of 687156840 is about 26213.6765830358. The cubic root of 687156840 is about 882.4402140186.

The spelling of 687156840 in words is "six hundred eighty-seven million, one hundred fifty-six thousand, eight hundred forty".