138138100 has 18 divisors (see below), whose sum is σ = 299759894. Its totient is φ = 55255200.

The previous prime is 138138089. The next prime is 138138103. The reversal of 138138100 is 1831831.

It can be written as a sum of positive squares in 3 ways, for example, as 5934096 + 132204004 = 2436^2 + 11498^2 .

It is a super-2 number, since 2×138138100² = 38164269343220000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138138103) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 690591 + ... + 690790.

Almost surely, 2^138138100 is an apocalyptic number.

138138100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

138138100 is an abundant number, since it is smaller than the sum of its proper divisors (161621794).

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

138138100 is a wasteful number, since it uses less digits than its factorization.

138138100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1381395 (or 1381388 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 138138100 is about 11753.2165810045. The cubic root of 138138100 is about 516.9372475643.

Adding to 138138100 its reverse (1831831), we get a palindrome (139969931).

The spelling of 138138100 in words is "one hundred thirty-eight million, one hundred thirty-eight thousand, one hundred".