102640678649 has 4 divisors (see below), whose sum is σ = 102684563280. Its totient is φ = 102596794020.

The previous prime is 102640678633. The next prime is 102640678681. The reversal of 102640678649 is 946876046201.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 102640678649 - 2⁴ = 102640678633 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 102640678649.

It is not an unprimeable number, because it can be changed into a prime (102640678249) 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, 21938807 + ... + 21943484.

It is an arithmetic number, because the mean of its divisors is an integer number (25671140820).

Almost surely, 2^102640678649 is an apocalyptic number.

It is an amenable number.

102640678649 is a deficient number, since it is larger than the sum of its proper divisors (43884631).

102640678649 is an equidigital number, since it uses as much as digits as its factorization.

102640678649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43884630.

The product of its (nonzero) digits is 3483648, while the sum is 53.

The spelling of 102640678649 in words is "one hundred two billion, six hundred forty million, six hundred seventy-eight thousand, six hundred forty-nine".