687633408 has 704 divisors, whose sum is σ = 2829772800. Its totient is φ = 159252480.

The previous prime is 687633407. The next prime is 687633409. The reversal of 687633408 is 804336786.

687633408 is a `hidden beast` number, since 6 + 8 + 7 + 633 + 4 + 0 + 8 = 666.

It is an interprime number because it is at equal distance from previous prime (687633407) and next prime (687633409).

It is a tau number, because it is divible by the number of its divisors (704).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (687633407) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 36191223 + ... + 36191241.

Almost surely, 2^687633408 is an apocalyptic number.

687633408 is a gapful number since it is divisible by the number (68) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 687633408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1414886400).

687633408 is an abundant number, since it is smaller than the sum of its proper divisors (2142139392).

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

687633408 is a wasteful number, since it uses less digits than its factorization.

687633408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83 (or 59 counting only the distinct ones).

The product of its (nonzero) digits is 580608, while the sum is 45.

The square root of 687633408 is about 26222.7650715938. The cubic root of 687633408 is about 882.6441682255.

The spelling of 687633408 in words is "six hundred eighty-seven million, six hundred thirty-three thousand, four hundred eight".