135981216 has 144 divisors (see below), whose sum is σ = 454132224. Its totient is φ = 37780992.

The previous prime is 135981211. The next prime is 135981227. The reversal of 135981216 is 612189531.

It is a tau number, because it is divible by the number of its divisors (144).

It is a super-2 number, since 2×135981216² = 36981782209677312, which contains 22 as substring.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

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

It is not an unprimeable number, because it can be changed into a prime (135981211) 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, 73681 + ... + 75503.

It is an arithmetic number, because the mean of its divisors is an integer number (3153696).

Almost surely, 2^135981216 is an apocalyptic number.

135981216 is a gapful number since it is divisible by the number (16) 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 135981216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (227066112).

135981216 is an abundant number, since it is smaller than the sum of its proper divisors (318151008).

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

135981216 is a wasteful number, since it uses less digits than its factorization.

135981216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1883 (or 1872 counting only the distinct ones).

The product of its digits is 12960, while the sum is 36.

The square root of 135981216 is about 11661.0984045243. The cubic root of 135981216 is about 514.2326410840.

The spelling of 135981216 in words is "one hundred thirty-five million, nine hundred eighty-one thousand, two hundred sixteen".