123991828779 has 64 divisors (see below), whose sum is σ = 216180486144. Its totient is φ = 61344331776.

The previous prime is 123991828739. The next prime is 123991828781. The reversal of 123991828779 is 977828199321.

It is not a de Polignac number, because 123991828779 - 2²¹ = 123989731627 is a prime.

It is not an unprimeable number, because it can be changed into a prime (123991828739) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1314222 + ... + 1405404.

It is an arithmetic number, because the mean of its divisors is an integer number (3377820096).

Almost surely, 2^123991828779 is an apocalyptic number.

123991828779 is a deficient number, since it is larger than the sum of its proper divisors (92188657365).

123991828779 is a wasteful number, since it uses less digits than its factorization.

123991828779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91516.

The product of its digits is 27433728, while the sum is 66.

The spelling of 123991828779 in words is "one hundred twenty-three billion, nine hundred ninety-one million, eight hundred twenty-eight thousand, seven hundred seventy-nine".