123999011536 has 20 divisors (see below), whose sum is σ = 248532502500. Its totient is φ = 59861591552.

The previous prime is 123999011531. The next prime is 123999011537. The reversal of 123999011536 is 635110999321.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 78655567936 + 45343443600 = 280456^2 + 212940^2 .

It is a super-2 number, since 2×123999011536² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 123999011536.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123999011531) 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, 133619161 + ... + 133620088.

It is an arithmetic number, because the mean of its divisors is an integer number (12426625125).

Almost surely, 2^123999011536 is an apocalyptic number.

123999011536 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

123999011536 is an abundant number, since it is smaller than the sum of its proper divisors (124533490964).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

123999011536 is a wasteful number, since it uses less digits than its factorization.

123999011536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 267239286 (or 267239280 counting only the distinct ones).

The product of its (nonzero) digits is 393660, while the sum is 49.

The spelling of 123999011536 in words is "one hundred twenty-three billion, nine hundred ninety-nine million, eleven thousand, five hundred thirty-six".