138948840 has 96 divisors (see below), whose sum is σ = 455855400. Its totient is φ = 36702720.

The previous prime is 138948833. The next prime is 138948883. The reversal of 138948840 is 48849831.

It can be written as a sum of positive squares in 4 ways, for example, as 117548964 + 21399876 = 10842^2 + 4626^2 .

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 23 ways as a sum of consecutive naturals, for example, 37470 + ... + 41010.

Almost surely, 2^138948840 is an apocalyptic number.

138948840 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 138948840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (227927700).

138948840 is an abundant number, since it is smaller than the sum of its proper divisors (316906560).

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

138948840 is a wasteful number, since it uses less digits than its factorization.

138948840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3667 (or 3660 counting only the distinct ones).

The product of its (nonzero) digits is 221184, while the sum is 45.

The square root of 138948840 is about 11787.6562555921. The cubic root of 138948840 is about 517.9465864236.

Subtracting from 138948840 its reverse (48849831), we obtain a palindrome (90099009).

The spelling of 138948840 in words is "one hundred thirty-eight million, nine hundred forty-eight thousand, eight hundred forty".