123638336640 has 1152 divisors, whose sum is σ = 552607211520. Its totient is φ = 25221611520.

The previous prime is 123638336639. The next prime is 123638336659. The reversal of 123638336640 is 46633836321.

123638336640 is a `hidden beast` number, since 1 + 2 + 3 + 638 + 3 + 3 + 6 + 6 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1152).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 113742177 + ... + 113743263.

It is an arithmetic number, because the mean of its divisors is an integer number (479693760).

Almost surely, 2^123638336640 is an apocalyptic number.

123638336640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 123638336640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (276303605760).

123638336640 is an abundant number, since it is smaller than the sum of its proper divisors (428968874880).

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

123638336640 is a wasteful number, since it uses less digits than its factorization.

123638336640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1170 (or 1148 counting only the distinct ones).

The product of its (nonzero) digits is 1119744, while the sum is 45.

The spelling of 123638336640 in words is "one hundred twenty-three billion, six hundred thirty-eight million, three hundred thirty-six thousand, six hundred forty".