687068601421 has 4 divisors (see below), whose sum is σ = 687319267644. Its totient is φ = 686817935200.

The previous prime is 687068601419. The next prime is 687068601469. The reversal of 687068601421 is 124106860786.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 124106860786 = 2 ⋅62053430393.

It can be written as a sum of positive squares in 2 ways, for example, as 211259736900 + 475808864521 = 459630^2 + 689789^2 .

It is a cyclic number.

It is not a de Polignac number, because 687068601421 - 2¹ = 687068601419 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (687068601491) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 125329000 + ... + 125334481.

It is an arithmetic number, because the mean of its divisors is an integer number (171829816911).

Almost surely, 2^687068601421 is an apocalyptic number.

It is an amenable number.

687068601421 is a deficient number, since it is larger than the sum of its proper divisors (250666223).

687068601421 is a wasteful number, since it uses less digits than its factorization.

687068601421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 250666222.

The product of its (nonzero) digits is 774144, while the sum is 49.

The spelling of 687068601421 in words is "six hundred eighty-seven billion, sixty-eight million, six hundred one thousand, four hundred twenty-one".