66531136 has 56 divisors (see below), whose sum is σ = 152538176. Its totient is φ = 28200960.

The previous prime is 66531131. The next prime is 66531137. The reversal of 66531136 is 63113566.

It is a tau number, because it is divible by the number of its divisors (56).

It is a junction number, because it is equal to n+sod(n) for n = 66531098 and 66531107.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66531131) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42691 + ... + 44221.

It is an arithmetic number, because the mean of its divisors is an integer number (2723896).

Almost surely, 2^66531136 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 66531136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (76269088).

66531136 is an abundant number, since it is smaller than the sum of its proper divisors (86007040).

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

66531136 is a wasteful number, since it uses less digits than its factorization.

66531136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1647 (or 1637 counting only the distinct ones).

The product of its digits is 9720, while the sum is 31.

The square root of 66531136 is about 8156.6620623880. The cubic root of 66531136 is about 405.2051716617.

The spelling of 66531136 in words is "sixty-six million, five hundred thirty-one thousand, one hundred thirty-six".