136991808 has 84 divisors (see below), whose sum is σ = 401866608. Its totient is φ = 44593920.

The previous prime is 136991801. The next prime is 136991819. The reversal of 136991808 is 808199631.

It is not an unprimeable number, because it can be changed into a prime (136991801) 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, 22003 + ... + 27533.

Almost surely, 2^136991808 is an apocalyptic number.

136991808 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 136991808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (200933304).

136991808 is an abundant number, since it is smaller than the sum of its proper divisors (264874800).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

136991808 is a wasteful number, since it uses less digits than its factorization.

136991808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5592 (or 5579 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 45.

The square root of 136991808 is about 11704.3499605916. The cubic root of 136991808 is about 515.5033981894.

The spelling of 136991808 in words is "one hundred thirty-six million, nine hundred ninety-one thousand, eight hundred eight".