687421111 has 4 divisors (see below), whose sum is σ = 740299672. Its totient is φ = 634542552.

The previous prime is 687421103. The next prime is 687421151. The reversal of 687421111 is 111124786.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 111124786 = 2 ⋅55562393.

It is a cyclic number.

It is not a de Polignac number, because 687421111 - 2³ = 687421103 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 (687421151) 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, 26439261 + ... + 26439286.

It is an arithmetic number, because the mean of its divisors is an integer number (185074918).

Almost surely, 2^687421111 is an apocalyptic number.

687421111 is a deficient number, since it is larger than the sum of its proper divisors (52878561).

687421111 is a wasteful number, since it uses less digits than its factorization.

687421111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52878560.

The product of its digits is 2688, while the sum is 31.

The square root of 687421111 is about 26218.7168068920. The cubic root of 687421111 is about 882.5533242796.

Adding to 687421111 its reverse (111124786), we get a palindrome (798545897).

The spelling of 687421111 in words is "six hundred eighty-seven million, four hundred twenty-one thousand, one hundred eleven".