138849021 has 12 divisors (see below), whose sum is σ = 205224448. Its totient is φ = 90413064.

The previous prime is 138848987. The next prime is 138849023. The reversal of 138849021 is 120948831.

It is not a de Polignac number, because 138849021 - 2¹³ = 138840829 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138849023) 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, 179005 + ... + 179778.

Almost surely, 2^138849021 is an apocalyptic number.

It is an amenable number.

138849021 is a deficient number, since it is larger than the sum of its proper divisors (66375427).

138849021 is a wasteful number, since it uses less digits than its factorization.

138849021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 358832 (or 358829 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 138849021 is about 11783.4214471010. The cubic root of 138849021 is about 517.8225280635.

The spelling of 138849021 in words is "one hundred thirty-eight million, eight hundred forty-nine thousand, twenty-one".