687561264 has 160 divisors (see below), whose sum is σ = 2218191360. Its totient is φ = 202321152.

The previous prime is 687561257. The next prime is 687561283. The reversal of 687561264 is 462165786.

687561264 is a `hidden beast` number, since 6 + 87 + 561 + 2 + 6 + 4 = 666.

687561264 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

Its product of digits (483840) is a multiple of the sum of its prime factors (5376).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 126507 + ... + 131829.

It is an arithmetic number, because the mean of its divisors is an integer number (13863696).

Almost surely, 2^687561264 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 687561264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1109095680).

687561264 is an abundant number, since it is smaller than the sum of its proper divisors (1530630096).

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

687561264 is a wasteful number, since it uses less digits than its factorization.

687561264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5376 (or 5364 counting only the distinct ones).

The product of its digits is 483840, while the sum is 45.

The square root of 687561264 is about 26221.3894368700. The cubic root of 687561264 is about 882.6132992056.

The spelling of 687561264 in words is "six hundred eighty-seven million, five hundred sixty-one thousand, two hundred sixty-four".