687626820 has 144 divisors (see below), whose sum is σ = 2179701888. Its totient is φ = 181958400.

The previous prime is 687626813. The next prime is 687626839. The reversal of 687626820 is 28626786.

It is a happy number.

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 47 ways as a sum of consecutive naturals, for example, 733392 + ... + 734328.

Almost surely, 2^687626820 is an apocalyptic number.

687626820 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 687626820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1089850944).

687626820 is an abundant number, since it is smaller than the sum of its proper divisors (1492075068).

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

687626820 is a wasteful number, since it uses less digits than its factorization.

687626820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1112 (or 1098 counting only the distinct ones).

The product of its (nonzero) digits is 387072, while the sum is 45.

The square root of 687626820 is about 26222.6394552494. The cubic root of 687626820 is about 882.6413494375.

The spelling of 687626820 in words is "six hundred eighty-seven million, six hundred twenty-six thousand, eight hundred twenty".