66531456 has 224 divisors, whose sum is σ = 214053120. Its totient is φ = 20528640.

The previous prime is 66531403. The next prime is 66531457. The reversal of 66531456 is 65413566.

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 66531456.

It is not an unprimeable number, because it can be changed into a prime (66531457) by changing a digit.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 2146161 + ... + 2146191.

Almost surely, 2^66531456 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 66531456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (107026560).

66531456 is an abundant number, since it is smaller than the sum of its proper divisors (147521664).

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

66531456 is an equidigital number, since it uses as much as digits as its factorization.

66531456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86 (or 59 counting only the distinct ones).

The product of its digits is 64800, while the sum is 36.

The square root of 66531456 is about 8156.6816782317. The cubic root of 66531456 is about 405.2058213097.

The spelling of 66531456 in words is "sixty-six million, five hundred thirty-one thousand, four hundred fifty-six".