123778671609 has 4 divisors (see below), whose sum is σ = 165038228816. Its totient is φ = 82519114404.

The previous prime is 123778671607. The next prime is 123778671617. The reversal of 123778671609 is 906176877321.

It is a happy number.

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 not a de Polignac number, because 123778671609 - 2¹ = 123778671607 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (123778671607) 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, 20629778599 + ... + 20629778604.

It is an arithmetic number, because the mean of its divisors is an integer number (41259557204).

Almost surely, 2^123778671609 is an apocalyptic number.

It is an amenable number.

123778671609 is a deficient number, since it is larger than the sum of its proper divisors (41259557207).

123778671609 is an equidigital number, since it uses as much as digits as its factorization.

123778671609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41259557206.

The product of its (nonzero) digits is 5334336, while the sum is 57.

The spelling of 123778671609 in words is "one hundred twenty-three billion, seven hundred seventy-eight million, six hundred seventy-one thousand, six hundred nine".