138835890 has 64 divisors (see below), whose sum is σ = 372136320. Its totient is φ = 36832320.

The previous prime is 138835883. The next prime is 138835891. The reversal of 138835890 is 98538831.

138835890 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not an unprimeable number, because it can be changed into a prime (138835891) 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, 55752 + ... + 58188.

It is an arithmetic number, because the mean of its divisors is an integer number (5814630).

Almost surely, 2^138835890 is an apocalyptic number.

138835890 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 138835890, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (186068160).

138835890 is an abundant number, since it is smaller than the sum of its proper divisors (233300430).

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

138835890 is a wasteful number, since it uses less digits than its factorization.

138835890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2664 (or 2658 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 45.

The square root of 138835890 is about 11782.8642528037. The cubic root of 138835890 is about 517.8062039970.

The spelling of 138835890 in words is "one hundred thirty-eight million, eight hundred thirty-five thousand, eight hundred ninety".