687246021 has 36 divisors (see below), whose sum is σ = 1259747424. Its totient is φ = 357008400.

The previous prime is 687246011. The next prime is 687246041. The reversal of 687246021 is 120642786.

687246021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 687246021 - 2²⁵ = 653691589 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (687246011) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 65985 + ... + 75686.

It is an arithmetic number, because the mean of its divisors is an integer number (34992984).

Almost surely, 2^687246021 is an apocalyptic number.

It is an amenable number.

687246021 is a deficient number, since it is larger than the sum of its proper divisors (572501403).

687246021 is a wasteful number, since it uses less digits than its factorization.

687246021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 141702 (or 141692 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 36.

The square root of 687246021 is about 26215.3775673745. The cubic root of 687246021 is about 882.4783874951.

The spelling of 687246021 in words is "six hundred eighty-seven million, two hundred forty-six thousand, twenty-one".