687064821 has 8 divisors (see below), whose sum is σ = 917396064. Its totient is φ = 457388400.

The previous prime is 687064801. The next prime is 687064841. The reversal of 687064821 is 128460786.

It is an interprime number because it is at equal distance from previous prime (687064801) and next prime (687064841).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 687064821 - 2⁵ = 687064789 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (687064801) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 161251 + ... + 165456.

It is an arithmetic number, because the mean of its divisors is an integer number (114674508).

Almost surely, 2^687064821 is an apocalyptic number.

It is an amenable number.

687064821 is a deficient number, since it is larger than the sum of its proper divisors (230331243).

687064821 is a wasteful number, since it uses less digits than its factorization.

687064821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 327411.

The product of its (nonzero) digits is 129024, while the sum is 42.

The square root of 687064821 is about 26211.9213526975. The cubic root of 687064821 is about 882.4008222882.

The spelling of 687064821 in words is "six hundred eighty-seven million, sixty-four thousand, eight hundred twenty-one".