136408581 has 12 divisors (see below), whose sum is σ = 207405120. Its totient is φ = 86152680.

The previous prime is 136408579. The next prime is 136408637. The reversal of 136408581 is 185804631.

136408581 is a `hidden beast` number, since 1 + 3 + 640 + 8 + 5 + 8 + 1 = 666.

It is not a de Polignac number, because 136408581 - 2¹ = 136408579 is a prime.

It is a super-2 number, since 2×136408581² = 37214601940867122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (136408081) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 398685 + ... + 399026.

It is an arithmetic number, because the mean of its divisors is an integer number (17283760).

Almost surely, 2^136408581 is an apocalyptic number.

It is an amenable number.

136408581 is a deficient number, since it is larger than the sum of its proper divisors (70996539).

136408581 is a wasteful number, since it uses less digits than its factorization.

136408581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 797736 (or 797733 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The square root of 136408581 is about 11679.4084182376. The cubic root of 136408581 is about 514.7707918979.

The spelling of 136408581 in words is "one hundred thirty-six million, four hundred eight thousand, five hundred eighty-one".