136521756 has 72 divisors (see below), whose sum is σ = 395871840. Its totient is φ = 38860416.

The previous prime is 136521743. The next prime is 136521757. The reversal of 136521756 is 657125631.

It is a super-2 number, since 2×136521756² = 37276379722647072, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 136521756.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (136521757) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 79030 + ... + 80738.

It is an arithmetic number, because the mean of its divisors is an integer number (5498220).

Almost surely, 2^136521756 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 136521756, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (197935920).

136521756 is an abundant number, since it is smaller than the sum of its proper divisors (259350084).

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

136521756 is a wasteful number, since it uses less digits than its factorization.

136521756 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2043 (or 2038 counting only the distinct ones).

The product of its digits is 37800, while the sum is 36.

The square root of 136521756 is about 11684.2524792988. The cubic root of 136521756 is about 514.9131169610.

The spelling of 136521756 in words is "one hundred thirty-six million, five hundred twenty-one thousand, seven hundred fifty-six".