133987644 has 72 divisors (see below), whose sum is σ = 390001248. Its totient is φ = 37992960.

The previous prime is 133987621. The next prime is 133987661. The reversal of 133987644 is 446789331.

It is a self number, because there is not a number n which added to its sum of digits gives 133987644.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 32584 + ... + 36464.

It is an arithmetic number, because the mean of its divisors is an integer number (5416684).

Almost surely, 2^133987644 is an apocalyptic number.

133987644 is a gapful number since it is divisible by the number (14) 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 133987644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (195000624).

133987644 is an abundant number, since it is smaller than the sum of its proper divisors (256013604).

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

133987644 is a wasteful number, since it uses less digits than its factorization.

133987644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4035 (or 4030 counting only the distinct ones).

The product of its digits is 435456, while the sum is 45.

The square root of 133987644 is about 11575.3031925734. The cubic root of 133987644 is about 511.7072657268.

The spelling of 133987644 in words is "one hundred thirty-three million, nine hundred eighty-seven thousand, six hundred forty-four".