123617637649 has 9 divisors (see below), whose sum is σ = 135881489289. Its totient is φ = 112376154660.

The previous prime is 123617637629. The next prime is 123617637673. The reversal of 123617637649 is 946736716321.

The square root of 123617637649 is 351593.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 123617637649 - 2²⁷ = 123483419921 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 123617637649.

It is not an unprimeable number, because it can be changed into a prime (123617637629) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 3851542 + ... + 3883504.

Almost surely, 2^123617637649 is an apocalyptic number.

123617637649 is the 351593-rd square number.

123617637649 is the 175797-th centered octagonal number.

It is an amenable number.

123617637649 is a deficient number, since it is larger than the sum of its proper divisors (12263851640).

123617637649 is an frugal number, since it uses more digits than its factorization.

123617637649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63948 (or 31974 counting only the distinct ones).

The product of its digits is 6858432, while the sum is 55.

The spelling of 123617637649 in words is "one hundred twenty-three billion, six hundred seventeen million, six hundred thirty-seven thousand, six hundred forty-nine".