138121533 has 12 divisors (see below), whose sum is σ = 217646208. Its totient is φ = 83709960.

The previous prime is 138121457. The next prime is 138121541. The reversal of 138121533 is 335121831.

138121533 is a `hidden beast` number, since 1 + 3 + 8 + 121 + 533 = 666.

138121533 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 138121533 - 2¹² = 138117437 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 138121497 and 138121506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138121573) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 697485 + ... + 697682.

It is an arithmetic number, because the mean of its divisors is an integer number (18137184).

Almost surely, 2^138121533 is an apocalyptic number.

It is an amenable number.

138121533 is a deficient number, since it is larger than the sum of its proper divisors (79524675).

138121533 is a wasteful number, since it uses less digits than its factorization.

138121533 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1395184 (or 1395181 counting only the distinct ones).

The product of its digits is 2160, while the sum is 27.

The square root of 138121533 is about 11752.5117740847. The cubic root of 138121533 is about 516.9165811882.

The spelling of 138121533 in words is "one hundred thirty-eight million, one hundred twenty-one thousand, five hundred thirty-three".