687357367391 has 4 divisors (see below), whose sum is σ = 687701220000. Its totient is φ = 687013514784.

The previous prime is 687357367373. The next prime is 687357367421. The reversal of 687357367391 is 193763753786.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 193763753786 = 2 ⋅96881876893.

It is a cyclic number.

It is not a de Polignac number, because 687357367391 - 2²⁶ = 687290258527 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (687357367691) 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, 171923306 + ... + 171927303.

It is an arithmetic number, because the mean of its divisors is an integer number (171925305000).

Almost surely, 2^687357367391 is an apocalyptic number.

687357367391 is a deficient number, since it is larger than the sum of its proper divisors (343852609).

687357367391 is a wasteful number, since it uses less digits than its factorization.

687357367391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 343852608.

The product of its digits is 120022560, while the sum is 65.

The spelling of 687357367391 in words is "six hundred eighty-seven billion, three hundred fifty-seven million, three hundred sixty-seven thousand, three hundred ninety-one".