136782391 has 4 divisors (see below), whose sum is σ = 144828432. Its totient is φ = 128736352.

The previous prime is 136782389. The next prime is 136782413. The reversal of 136782391 is 193287631.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 193287631 = 71 ⋅2722361.

It is a cyclic number.

It is not a de Polignac number, because 136782391 - 2¹ = 136782389 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 (136782301) 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, 4022995 + ... + 4023028.

It is an arithmetic number, because the mean of its divisors is an integer number (36207108).

Almost surely, 2^136782391 is an apocalyptic number.

136782391 is a deficient number, since it is larger than the sum of its proper divisors (8046041).

136782391 is an equidigital number, since it uses as much as digits as its factorization.

136782391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8046040.

The product of its digits is 54432, while the sum is 40.

The square root of 136782391 is about 11695.4004206782. The cubic root of 136782391 is about 515.2405838572.

The spelling of 136782391 in words is "one hundred thirty-six million, seven hundred eighty-two thousand, three hundred ninety-one".