687155259840 has 672 divisors, whose sum is σ = 2642136122880. Its totient is φ = 148043685888.

The previous prime is 687155259839. The next prime is 687155259859. The reversal of 687155259840 is 48952551786.

It is a tau number, because it is divible by the number of its divisors (672).

It is a super-2 number, since 2×687155259840² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (60).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 360332167 + ... + 360334073.

Almost surely, 2^687155259840 is an apocalyptic number.

687155259840 is a gapful number since it is divisible by the number (60) 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 687155259840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1321068061440).

687155259840 is an abundant number, since it is smaller than the sum of its proper divisors (1954980863040).

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

687155259840 is a wasteful number, since it uses less digits than its factorization.

687155259840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2049 (or 1996 counting only the distinct ones).

The product of its (nonzero) digits is 24192000, while the sum is 60.

The spelling of 687155259840 in words is "six hundred eighty-seven billion, one hundred fifty-five million, two hundred fifty-nine thousand, eight hundred forty".