138690779850 has 288 divisors, whose sum is σ = 443531612160. Its totient is φ = 31563483840.

The previous prime is 138690779779. The next prime is 138690779911. The reversal of 138690779850 is 58977096831.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 20323539 + ... + 20330361.

It is an arithmetic number, because the mean of its divisors is an integer number (1540040320).

Almost surely, 2^138690779850 is an apocalyptic number.

138690779850 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 138690779850, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (221765806080).

138690779850 is an abundant number, since it is smaller than the sum of its proper divisors (304840832310).

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

138690779850 is a wasteful number, since it uses less digits than its factorization.

138690779850 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7096 (or 7079 counting only the distinct ones).

The product of its (nonzero) digits is 22861440, while the sum is 63.

The spelling of 138690779850 in words is "one hundred thirty-eight billion, six hundred ninety million, seven hundred seventy-nine thousand, eight hundred fifty".