66401544 has 64 divisors (see below), whose sum is σ = 183032640. Its totient is φ = 19906560.

The previous prime is 66401539. The next prime is 66401557. The reversal of 66401544 is 44510466.

66401544 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24312 + ... + 26904.

It is an arithmetic number, because the mean of its divisors is an integer number (2859885).

Almost surely, 2^66401544 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 66401544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (91516320).

66401544 is an abundant number, since it is smaller than the sum of its proper divisors (116631096).

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

66401544 is a wasteful number, since it uses less digits than its factorization.

66401544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2710 (or 2706 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 30.

The square root of 66401544 is about 8148.7142544085. The cubic root of 66401544 is about 404.9419090588.

It can be divided in two parts, 66 and 401544, that multiplied together give a square (26501904 = 5148²).

The spelling of 66401544 in words is "sixty-six million, four hundred one thousand, five hundred forty-four".