138211511 has 4 divisors (see below), whose sum is σ = 140158224. Its totient is φ = 136264800.

The previous prime is 138211501. The next prime is 138211561. The reversal of 138211511 is 115112831.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 138211511 - 2¹⁰ = 138210487 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 (138211501) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 973250 + ... + 973391.

It is an arithmetic number, because the mean of its divisors is an integer number (35039556).

Almost surely, 2^138211511 is an apocalyptic number.

138211511 is a deficient number, since it is larger than the sum of its proper divisors (1946713).

138211511 is an equidigital number, since it uses as much as digits as its factorization.

138211511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1946712.

The product of its digits is 240, while the sum is 23.

The square root of 138211511 is about 11756.3391836064. The cubic root of 138211511 is about 517.0288036709.

The spelling of 138211511 in words is "one hundred thirty-eight million, two hundred eleven thousand, five hundred eleven".