138721100 has 36 divisors (see below), whose sum is σ = 344030064. Its totient is φ = 47561280.

The previous prime is 138721057. The next prime is 138721117. The reversal of 138721100 is 1127831.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 98387 + ... + 99786.

Almost surely, 2^138721100 is an apocalyptic number.

138721100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

138721100 is an abundant number, since it is smaller than the sum of its proper divisors (205308964).

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

138721100 is a wasteful number, since it uses less digits than its factorization.

138721100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198194 (or 198187 counting only the distinct ones).

The product of its (nonzero) digits is 336, while the sum is 23.

The square root of 138721100 is about 11777.9921888240. The cubic root of 138721100 is about 517.6634566542.

Adding to 138721100 its reverse (1127831), we get a palindrome (139848931).

The spelling of 138721100 in words is "one hundred thirty-eight million, seven hundred twenty-one thousand, one hundred".