687780072 has 120 divisors (see below), whose sum is σ = 2241042210. Its totient is φ = 196499520.

The previous prime is 687780029. The next prime is 687780073. The reversal of 687780072 is 270087786.

It can be written as a sum of positive squares in only one way, i.e., 628705476 + 59074596 = 25074^2 + 7686^2 .

It is not an unprimeable number, because it can be changed into a prime (687780073) by changing a digit.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 20922 + ... + 42582.

Almost surely, 2^687780072 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 687780072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1120521105).

687780072 is an abundant number, since it is smaller than the sum of its proper divisors (1553262138).

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

687780072 is a wasteful number, since it uses less digits than its factorization.

687780072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21693 (or 21673 counting only the distinct ones).

The product of its (nonzero) digits is 263424, while the sum is 45.

The square root of 687780072 is about 26225.5614239238. The cubic root of 687780072 is about 882.7069162539.

The spelling of 687780072 in words is "six hundred eighty-seven million, seven hundred eighty thousand, seventy-two".