687611819 has 4 divisors (see below), whose sum is σ = 688260960. Its totient is φ = 686962680.

The previous prime is 687611807. The next prime is 687611863. The reversal of 687611819 is 918116786.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 687611819 - 2²⁸ = 419176363 is a prime.

It is a super-2 number, since 2×687611819² = 945620027256977522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (687611879) 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, 322979 + ... + 325100.

It is an arithmetic number, because the mean of its divisors is an integer number (172065240).

Almost surely, 2^687611819 is an apocalyptic number.

687611819 is a deficient number, since it is larger than the sum of its proper divisors (649141).

687611819 is a wasteful number, since it uses less digits than its factorization.

687611819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 649140.

The product of its digits is 145152, while the sum is 47.

The square root of 687611819 is about 26222.3534222236. The cubic root of 687611819 is about 882.6349309370.

The spelling of 687611819 in words is "six hundred eighty-seven million, six hundred eleven thousand, eight hundred nineteen".