136978686 has 48 divisors (see below), whose sum is σ = 324424464. Its totient is φ = 41513472.

The previous prime is 136978649. The next prime is 136978691. The reversal of 136978686 is 686879631.

It is a happy number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11310 + ... + 20046.

It is an arithmetic number, because the mean of its divisors is an integer number (6758843).

Almost surely, 2^136978686 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 136978686, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (162212232).

136978686 is an abundant number, since it is smaller than the sum of its proper divisors (187445778).

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

136978686 is a wasteful number, since it uses less digits than its factorization.

136978686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8825 (or 8822 counting only the distinct ones).

The product of its digits is 2612736, while the sum is 54.

The square root of 136978686 is about 11703.7893863483. The cubic root of 136978686 is about 515.4869381989.

The spelling of 136978686 in words is "one hundred thirty-six million, nine hundred seventy-eight thousand, six hundred eighty-six".