138221511 has 8 divisors (see below), whose sum is σ = 190650480. Its totient is φ = 88970112.

The previous prime is 138221497. The next prime is 138221519. The reversal of 138221511 is 115122831.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 138221511 - 2⁷ = 138221383 is a prime.

It is a super-2 number, since 2×138221511² = 38210372206246242, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138221519) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 794290 + ... + 794463.

It is an arithmetic number, because the mean of its divisors is an integer number (23831310).

Almost surely, 2^138221511 is an apocalyptic number.

138221511 is a deficient number, since it is larger than the sum of its proper divisors (52428969).

138221511 is a wasteful number, since it uses less digits than its factorization.

138221511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1588785.

The product of its digits is 480, while the sum is 24.

The square root of 138221511 is about 11756.7644783758. The cubic root of 138221511 is about 517.0412728768.

The spelling of 138221511 in words is "one hundred thirty-eight million, two hundred twenty-one thousand, five hundred eleven".