123961208645 has 4 divisors (see below), whose sum is σ = 148753450380. Its totient is φ = 99168966912.

The previous prime is 123961208629. The next prime is 123961208663. The reversal of 123961208645 is 546802169321.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 546802169321 = 420349 ⋅1300829.

It can be written as a sum of positive squares in 2 ways, for example, as 44483449921 + 79477758724 = 210911^2 + 281918^2 .

It is a cyclic number.

It is not a de Polignac number, because 123961208645 - 2⁴ = 123961208629 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 123961208645.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12396120860 + ... + 12396120869.

It is an arithmetic number, because the mean of its divisors is an integer number (37188362595).

Almost surely, 2^123961208645 is an apocalyptic number.

It is an amenable number.

123961208645 is a deficient number, since it is larger than the sum of its proper divisors (24792241735).

123961208645 is an equidigital number, since it uses as much as digits as its factorization.

123961208645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24792241734.

The product of its (nonzero) digits is 622080, while the sum is 47.

The spelling of 123961208645 in words is "one hundred twenty-three billion, nine hundred sixty-one million, two hundred eight thousand, six hundred forty-five".