138863820 has 96 divisors (see below), whose sum is σ = 415800000. Its totient is φ = 34504704.

The previous prime is 138863807. The next prime is 138863827. The reversal of 138863820 is 28368831.

It is not an unprimeable number, because it can be changed into a prime (138863827) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 110556 + ... + 111804.

It is an arithmetic number, because the mean of its divisors is an integer number (4331250).

Almost surely, 2^138863820 is an apocalyptic number.

138863820 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 138863820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (207900000).

138863820 is an abundant number, since it is smaller than the sum of its proper divisors (276936180).

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

138863820 is a wasteful number, since it uses less digits than its factorization.

138863820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1387 (or 1385 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 39.

The square root of 138863820 is about 11784.0493888985. The cubic root of 138863820 is about 517.8409245042.

The spelling of 138863820 in words is "one hundred thirty-eight million, eight hundred sixty-three thousand, eight hundred twenty".