138424220 has 48 divisors (see below), whose sum is σ = 319038048. Its totient is φ = 50031360.

The previous prime is 138424171. The next prime is 138424261. The reversal of 138424220 is 22424831.

It is a super-2 number, since 2×138424220² = 38322529365216800, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 138424220.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36242 + ... + 39878.

It is an arithmetic number, because the mean of its divisors is an integer number (6646626).

Almost surely, 2^138424220 is an apocalyptic number.

138424220 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 138424220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (159519024).

138424220 is an abundant number, since it is smaller than the sum of its proper divisors (180613828).

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

138424220 is a wasteful number, since it uses less digits than its factorization.

138424220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3830 (or 3828 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 26.

The square root of 138424220 is about 11765.3822717326. The cubic root of 138424220 is about 517.2939053468.

The spelling of 138424220 in words is "one hundred thirty-eight million, four hundred twenty-four thousand, two hundred twenty".