136903681 has 4 divisors (see below), whose sum is σ = 138115332. Its totient is φ = 135692032.

The previous prime is 136903667. The next prime is 136903687. The reversal of 136903681 is 186309631.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 186309631 = 1733 ⋅107507.

It can be written as a sum of positive squares in 2 ways, for example, as 53802225 + 83101456 = 7335^2 + 9116^2 .

It is a cyclic number.

It is not a de Polignac number, because 136903681 - 2⁷ = 136903553 is a prime.

It is a super-2 number, since 2×136903681² = 37485235742699522, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 136903681.

It is not an unprimeable number, because it can be changed into a prime (136903687) 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, 605656 + ... + 605881.

It is an arithmetic number, because the mean of its divisors is an integer number (34528833).

Almost surely, 2^136903681 is an apocalyptic number.

It is an amenable number.

136903681 is a deficient number, since it is larger than the sum of its proper divisors (1211651).

136903681 is a wasteful number, since it uses less digits than its factorization.

136903681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1211650.

The product of its (nonzero) digits is 23328, while the sum is 37.

The square root of 136903681 is about 11700.5846435125. The cubic root of 136903681 is about 515.3928331520.

It can be divided in two parts, 13690 and 3681, that added together give a palindrome (17371).

The spelling of 136903681 in words is "one hundred thirty-six million, nine hundred three thousand, six hundred eighty-one".