66381744 has 160 divisors (see below), whose sum is σ = 212486400. Its totient is φ = 17556480.

The previous prime is 66381743. The next prime is 66381767. The reversal of 66381744 is 44718366.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is not an unprimeable number, because it can be changed into a prime (66381743) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 130162 + ... + 130670.

It is an arithmetic number, because the mean of its divisors is an integer number (1328040).

Almost surely, 2^66381744 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 66381744, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (106243200).

66381744 is an abundant number, since it is smaller than the sum of its proper divisors (146104656).

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

66381744 is a wasteful number, since it uses less digits than its factorization.

66381744 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 563 (or 557 counting only the distinct ones).

The product of its digits is 96768, while the sum is 39.

The square root of 66381744 is about 8147.4992482356. The cubic root of 66381744 is about 404.9016557435.

The spelling of 66381744 in words is "sixty-six million, three hundred eighty-one thousand, seven hundred forty-four".