138884261 has 4 divisors (see below), whose sum is σ = 142271724. Its totient is φ = 135496800.

The previous prime is 138884183. The next prime is 138884267. The reversal of 138884261 is 162488831.

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

It can be written as a sum of positive squares in 2 ways, for example, as 20205025 + 118679236 = 4495^2 + 10894^2 .

It is not a de Polignac number, because 138884261 - 2²² = 134689957 is a prime.

It is a super-2 number, since 2×138884261² = 38577675907032242, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (41), and also a Moran number because the ratio is a prime number: 3387421 = 138884261 / (1 + 3 + 8 + 8 + 8 + 4 + 2 + 6 + 1).

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138884267) 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, 1693670 + ... + 1693751.

It is an arithmetic number, because the mean of its divisors is an integer number (35567931).

Almost surely, 2^138884261 is an apocalyptic number.

It is an amenable number.

138884261 is a deficient number, since it is larger than the sum of its proper divisors (3387463).

138884261 is an equidigital number, since it uses as much as digits as its factorization.

138884261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3387462.

The product of its digits is 73728, while the sum is 41.

The square root of 138884261 is about 11784.9166734432. The cubic root of 138884261 is about 517.8663322910.

The spelling of 138884261 in words is "one hundred thirty-eight million, eight hundred eighty-four thousand, two hundred sixty-one".